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Photo by Stephen Jones. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615995625901-1YM1OC4V72OICFD93QG8/Swainsons-Hawk-Glenn-Cushman-blue-eyes-resize-300x200.jpg Articles - Nature Almanac, March 2021: Pampas Hawks Arrive on Schedule but Find Fewer Vacancies This handsome youngster fledged from a nest in a large cottonwood in Ruth Carol and Glenn Cushman’s front yard. 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BCAS runs or promotes different activities and opportunities, throughout the year, that provide educational opportunities on local plants, wildlife, and conservation. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333975207-569MILBGU37CE6T1PA3J/BurrowingOwls.jpg Boulder County Audubon Society - Advocacy Being a voice in our community for local and regional efforts to conserve habitats and species. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600030583315-7Q4EUJ7O7SM3WVC3SM8J/Browns-Park-National-Wildlife-Refuge.jpg Boulder County Audubon Society - Conservation Conservation is core to the founding and continued mission of Boulder County Audubon. Our focus on conservation reaches from creating habitat in backyards to monitoring native species around the region. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333792167-KDBSCIGT66AZGOFTSBW9/MembershipImage.jpg Boulder County Audubon Society - Membership in Boulder County Audubon has many advantages Early registration for Interludes trips Directly support BCAS programs, activities, and publications. Receive emailed issues of our On the Wing https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615997011969-P5TANVH3DVW8NZ5QI32E/Indian-Grass-300x201.png Boulder County Audubon Society - Read the latest articles from BCAS Nature Almanac, Teen Naturalists, Habitat Heroes, and more. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1598299116435-LYOEB094YUSMOBA0HTJB/MarshWren.jpg Boulder County Audubon Society - Donors Our direct donors provide vital support for all BCAS activities. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615935798359-DZL3XSFQR3BR20RUW194/FRBC_LogoFA.png Boulder County Audubon Society - Front Range Birding Company Front Range Birding Company, on Arapahoe in Boulder, provide quality seed, optics, and other goodies for any bird or nature enthusiast. A portion of all seed sales goes to support BCAS. FRBC also hosts birding walks and in-store events with local artists and authors. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615935122338-WGEFNO7EZ02UKINPLO7P/COGivesDay-ThankYou.jpg Boulder County Audubon Society - Colorado Gives Day BCAS receives a significant proportion of its funds to support educational programs through Colorado Gives. Please consider BCAS as part of your annual giving. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615936092801-7QWU4QYEPNE7LRNR1WIJ/SCFD_logo_Color_Horz.png Boulder County Audubon Society - Scientific & Cultural Facilities District SCFD makes our community more vibrant. https://www.kevinks.com/conservation daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600029349969-9JFK6GDN5KTBW80NV258/Backyard_Donna-Duffy-768x576.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600030583315-7Q4EUJ7O7SM3WVC3SM8J/Browns-Park-National-Wildlife-Refuge.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600030111041-OZHWFMU802Y7TQODMY9S/CheckingBox.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600031934553-CA1BTQ9EKV43Q8RZH3MQ/Dodd1.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587611475340-3ZH2ALYI7JCFF68MHYGL/Backyard_Donna-Duffy-768x576.jpeg Conservation Beautiful wildscaping by Donna Duffy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587611539955-7W2V915F7JU48FAVGZGH/CheckingBox.jpg Conservation Volunteer checking a bluebird box at Walker Ranch https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600029349969-9JFK6GDN5KTBW80NV258/Backyard_Donna-Duffy-768x576.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600030583315-7Q4EUJ7O7SM3WVC3SM8J/Browns-Park-National-Wildlife-Refuge.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600030111041-OZHWFMU802Y7TQODMY9S/CheckingBox.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1600031934553-CA1BTQ9EKV43Q8RZH3MQ/Dodd1.jpg Conservation https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587611475340-3ZH2ALYI7JCFF68MHYGL/Backyard_Donna-Duffy-768x576.jpeg Conservation Beautiful wildscaping by Donna Duffy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587611539955-7W2V915F7JU48FAVGZGH/CheckingBox.jpg Conservation Volunteer checking a bluebird box at Walker Ranch https://www.kevinks.com/about-bcas daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587607512082-66IUZ6SYH87X768OH134/burrowingowl1.jpg Mission Burrowing Owl. 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Photo © 2013, Matthew Studebaker https://www.kevinks.com/teen-naturalists daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591500102415-8YABVDH2YNBQFA3A9JT6/ColombiaTerns.jpg Teen Naturalists https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004814752-FYCJM7OIE8FC9L6LQ4NY/Group-300x199.png Teen Naturalists - What Are The Teen Naturalists up to? Read about the recent work done by and trips taken by BCAS Teen Naturalists. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587612219836-Y89GLRWOZJ1DE9T46GQ5/GHOW_Nest_EvaGetman.jpg Teen Naturalists A recent article by Eva highlights our fascination with nesting owls while pointing out the need to give them space. 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https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654380174-IS6EW6TNKOF0UPQDNYSU/big_crossbill.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654446981-FA9X7Q4FIOMZCB4KO7BV/big_IndianPeaksLongLake.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654464075-PTCRFANWVJ9TYVA4E5DU/big_Clarks_nutcracker.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654513534-4WYZ3SNWE306I0Q76NSS/big_OuzelFalls.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654529072-IIW79EY4UYR1ZG4LK113/big_dipper.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587653754660-T0YI709HBAPXIOGV9LKB/big_Yellow-headed-blackbird.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587653908698-CCD8NZDB4K5MIA6I8B5C/big_heron_ducks_mist.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587653969746-ZYYJB1RQYCX5Q4J4U68P/big_pelican.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654041984-SG0E8SD7E3VR75B96K5Z/big_mule_deer.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654125507-VJ8ONU6RO8ELSK92U1FZ/big_lazuli.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654168790-A56J192PW2WMAW8LDTSI/big_South-Mesa-Trail-Dunn-house.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654184064-RH823YPDY2DW2TSGI4PP/big_towheeSong.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654263494-I7XB8YYVAR1YML1CF1CV/big_chat.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654283142-46YRSKYSEBUCCKLJEACW/big_SpotTowhee.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654362341-FYWOC8IX2H6T9YFELVIJ/big_Meyers_HomesteadTrail.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654380174-IS6EW6TNKOF0UPQDNYSU/big_crossbill.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654446981-FA9X7Q4FIOMZCB4KO7BV/big_IndianPeaksLongLake.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654464075-PTCRFANWVJ9TYVA4E5DU/big_Clarks_nutcracker.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654513534-4WYZ3SNWE306I0Q76NSS/big_OuzelFalls.jpg Local Birding https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1587654529072-IIW79EY4UYR1ZG4LK113/big_dipper.jpg Local Birding https://www.kevinks.com/bird-galleries daily 0.75 2020-08-25 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904852020-3A3LIS6RROOOL223THSK/image-asset.jpeg Regional Birds - Female and Male Northern Shovelers (Copy) Female and Male Northern Shovelers https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904912365-0ZN5CPS7QSWIUUYJRBRS/image-asset.jpeg Regional Birds - American White Pelican in flight (Copy) American White Pelican in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904996329-2T5K5K1Z4UL4IP8NDTJU/image-asset.jpeg Regional Birds - Wilson's Snipe (Copy) Wilson's Snipe https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905048292-DIOZA9LXVOBERMA4YG8P/image-asset.jpeg Regional Birds - Sandhill Crane in flight (Copy) Sandhill Crane in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905084315-RZE6DE1MFA3RYIUMKJ9P/image-asset.jpeg Regional Birds - Snow Goose in flight (Copy) Snow Goose in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905135923-GVRXTZD45RUOLO8NDHCK/image-asset.jpeg Regional Birds - Greater Yellowlegs scaring minnows (Copy) Greater Yellowlegs scaring minnows https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905198484-O7ADBAQRB8JFCTWAQHUH/image-asset.jpeg Regional Birds - Broad-tailed Hummingbird (Copy) Broad-tailed Hummingbird https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905247265-RBD80KJ9FQIUY2CJVX0Y/image-asset.jpeg Regional Birds - Gray-headed Rosyfinch (Copy) Gray-headed Rosyfinch https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905284544-770JC802DPUZSK6ZZHRS/image-asset.jpeg Regional Birds - Singing Yellow-headed Blackbird (Copy) Singing Yellow-headed Blackbird https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588733920805-JU3ER89QCMGH384MV3LL/image-asset.jpeg Regional Birds - American Wigeon (m) (Copy) American Wigeon (m) - Status: Uncommon summer resident; common to abundant migrant and winter resident. - Populations: Nesting in Boulder County is poorly documented, but a few pairs appear to remain here throughout the summer. Breeding numbers are most concentrated from the Dakotas north and west to Alaska. Large flocks gather on prairie ponds, reservoirs, and streams in Boulder County from September-April. Look for them on Boulder Creek next to the Boulder Public Library and at Walden and Sawhill ponds. - Conservation: After a decade of decline during the 1980s, North American populations recovered to near-historic high levels of more than 3 million by 2000. Nesting success in eastern Colorado may be limited by lack of protective vegetation around lakes and reservoirs, as well as predation by bull snakes. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588734292418-LDTI1B9XK0HDLBUV08LJ/image-asset.jpeg Regional Birds - American Wigeon (f) (Copy) American Wigeon (f) - Status: Uncommon summer resident; common to abundant migrant and winter resident. - Populations: Nesting in Boulder County is poorly documented, but a few pairs appear to remain here throughout the summer. Breeding numbers are most concentrated from the Dakotas north and west to Alaska. Large flocks gather on prairie ponds, reservoirs, and streams in Boulder County from September-April. Look for them on Boulder Creek next to the Boulder Public Library and at Walden and Sawhill ponds. - Conservation: After a decade of decline during the 1980s, North American populations recovered to near-historic high levels of more than 3 million by 2000. Nesting success in eastern Colorado may be limited by lack of protective vegetation around lakes and reservoirs, as well as predation by bull snakes. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588736030696-EVX3DEKG8JQD0HLKE6OJ/image-asset.jpeg Regional Birds - Blue-winged Teal (m) (Copy) Blue-winged Teal (m) - Status: Fairly common summer resident and spring and fall migrant. - Populations: These dabblers gravitate to shallow ponds and mud flats. They nest on the ground amid concealing grasses or other low vegetation, sometimes far from water. Successful nesting in Boulder County is uncommon. They winter from California south to Brazil and Peru. Look for the first spring arrivals in March at Walden and Sawhill Ponds, Boulder Reservoir, and Baseline Reservoir. - Conservation: Second most abundant duck in North America. North American populations reached a 40-year low in 1990 after a period of drought on the northern plains. Numbers have more than doubled since then. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588736254127-YQO51H6YUGU7KKA77R14/image-asset.jpeg Regional Birds - Blue-winged Teal (f) (Copy) Blue-winged Teal (f) - Status: Fairly common summer resident and spring and fall migrant. - Populations: These dabblers gravitate to shallow ponds and mud flats. They nest on the ground amid concealing grasses or other low vegetation, sometimes far from water. Successful nesting in Boulder County is uncommon. They winter from California south to Brazil and Peru. Look for the first spring arrivals in March at Walden and Sawhill Ponds, Boulder Reservoir, and Baseline Reservoir. - Conservation: Second most abundant duck in North America. North American populations reached a 40-year low in 1990 after a period of drought on the northern plains. Numbers have more than doubled since then. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772337331-T4EDIVXNOJGGCL07PWBF/image-asset.jpeg Regional Birds - Canada Goose (Copy) Canada Goose - Status: Abundant year-round resident. - Populations: Flocks of hundreds to thousands of individuals inhabit ponds, agricultural fields, golf courses, and urban parks. Some stay year-round, others migrate north in summer or south and winter. - Conservation: Once rare in Boulder County, this cosmopolitan goose has adapted to suburban and rural life, taking advantage of seeds and invertebrates found in lawns, parks, and agricultural fields. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772460011-QV9UO1R4BSJS1X29FHTO/image-asset.jpeg Regional Birds - Cinnamon Teal (m) (Copy) Cinnamon Teal (m) - Status: Fairly common summer resident and spring migrant. Uncommon fall migrant. - Populations: These striking dabblers nest in similar sites to those used by Blue-winged Teal, and the two species are often seen together. Look for them out Walden Ponds, Boulder Reservoir, and Union Reservoir. In early fall, they migrate south to Mexico and South America. - Conservation: With a total North American population of around 300,000, this is one of our least, and dabbling ducks. Nesting success in Boulder County is limited by nest predation and a paucity of favorable nest sites. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772512183-KIP8JTKKYEGKE3775KR1/image-asset.jpeg Regional Birds - Cinnamon Teal (f) (Copy) Cinnamon Teal (f) - Status: Fairly common summer resident and spring migrant. Uncommon fall migrant. - Populations: These striking dabblers nest in similar sites to those used by Blue-winged Teal, and the two species are often seen together. Look for them out Walden Ponds, Boulder Reservoir, and Union Reservoir. In early fall, they migrate south to Mexico and South America. - Conservation: With a total North American population of around 300,000, this is one of our least, and dabbling ducks. Nesting success in Boulder County is limited by nest predation and a paucity of favorable nest sites. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772618369-HM98LBCHKWIHU5HSA7PD/image-asset.jpeg Regional Birds - Gadwall (m) (Copy) Gadwall (m) - Status: Uncommon summer resident; common winter resident and migrant. - Populations: A few pairs may nest each spring along the shores of our larger ponds and reservoirs on the plains. Large flocks gather on prairie ponds and reservoirs throughout the fall, winter, and spring. Listen for the deep grunting calls of the males. The first pond on the right at Sawhill Ponds supports 100 or more Gadwalls from March-April and October-December. - Conservation: North American populations more than doubled from 1986-1996 as wetlands were protected and enhanced throughout the Prairie Pothole Region and central Great Plains. Boulder County nesting populations are greatly limited by an absence of lakes with shallow, grassy shorelines for concealing nests. Bull snakes probably prey heavily on nests throughout eastern Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772684922-JNMLXICHUWHUTZ4MYUG3/image-asset.jpeg Regional Birds - Gadwall (f) (Copy) Gadwall (f) - Status: Uncommon summer resident; common winter resident and migrant. - Populations: A few pairs may nest each spring along the shores of our larger ponds and reservoirs on the plains. Large flocks gather on prairie ponds and reservoirs throughout the fall, winter, and spring. Listen for the deep grunting calls of the males. The first pond on the right at Sawhill Ponds supports 100 or more Gadwalls from March-April and October-December. - Conservation: North American populations more than doubled from 1986-1996 as wetlands were protected and enhanced throughout the Prairie Pothole Region and central Great Plains. Boulder County nesting populations are greatly limited by an absence of lakes with shallow, grassy shorelines for concealing nests. Bull snakes probably prey heavily on nests throughout eastern Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772730803-KBW0AUXAQKNGW6RWDM4M/image-asset.jpeg Regional Birds - Greater White-fronted Goose (Copy) Greater White-fronted Goose - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772824106-YSL3CTXWHTRLVWD2H0RW/image-asset.jpeg Regional Birds - Mallard (m) (Copy) Mallard (m) - Status: Abundant year-round resident. - Populations: These urban-adapted ducks nest on shorelines of streams, ponds, and reservoirs in Boulder County from the plains to the subalpine. They breed throughout North America from the U.S./Mexico border north to the Subarctic. - Conservation: More than 10 million currently breed in North America. Populations are stable or increasing throughout much of their breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772889832-ZZVK7HBDBXXLTUWZIY4N/image-asset.jpeg Regional Birds - Mallard (f) (Copy) Mallard (f) - Status: Abundant year-round resident. - Populations: These urban-adapted ducks nest on shorelines of streams, ponds, and reservoirs in Boulder County from the plains to the subalpine. They breed throughout North America from the U.S./Mexico border north to the Subarctic. - Conservation: More than 10 million currently breed in North America. Populations are stable or increasing throughout much of their breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772992744-CQDLC2HR3Q57FT3LM61B/image-asset.jpeg Regional Birds - Northern Shoveler (m) (Copy) Northern Shoveler (m) - Status: Uncommon summer resident, abundant to fairly common migrant and winter resident. - Populations: Northern Shovelers frequent shallow water of streams, ponds, and reservoirs. Look for them in spring and fall at Walden Ponds, Baseline Reservoir, and Union Reservoir. They nest from Colorado north through the Prairie Pothole region to Northwestern Canada and Alaska. Nesting in Boulder County is poorly documented. - Conservation: Loss of more than half of waterfowl nesting habitat throughout North America since the 1700s have hurt this and other species. About 150,000-200,000 Northern Shovelers are killed each year by hunters. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998403706-4N36PUADQ3U10EGMONMP/northernshoveler2.jpg Regional Birds - Northern Shoveler (f) (Copy) Northern Shoveler (f) - Status: Uncommon summer resident, abundant to fairly common migrant and winter resident. - Populations: Northern Shovelers frequent shallow water of streams, ponds, and reservoirs. Look for them in spring and fall at Walden Ponds, Baseline Reservoir, and Union Reservoir. They nest from Colorado north through the Prairie Pothole region to Northwestern Canada and Alaska. Nesting in Boulder County is poorly documented. - Conservation: Loss of more than half of waterfowl nesting habitat throughout North America since the 1700s have hurt this and other species. About 150,000-200,000 Northern Shovelers are killed each year by hunters. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591977555277-MU1PSL0XXQP8RVNF6IXW/image-asset.jpeg Regional Birds - Snow Goose in flight (Copy) Snow Goose in flight - Status: Uncommon migrant and rare winter visitor. - Populations: Stray individuals sometimes mix in with large flocks of Canada Geese during winter. Listen for large flocks passing high overhead in early spring and late fall. In winter, look for individuals at Valmont Reservoir and the White Rocks area. Up to 50,000 gather along the North Platte River between Oshkosh and Lake McConaghy in March. - Conservation: Nests from eastern Siberia across arctic plains of Alaska and Canada to Greenland. Total population may exceed 8,000,000, and increasing numbers have stressed Arctic breeding areas since pairs are reluctant to stray far from their home colonies. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591977754445-B70JVFSOZHSF0SNEKCMI/image-asset.jpeg Regional Birds - Trumpeter Swan with young (Copy) Trumpeter Swan with young - Status: Rare migrant and winter visitor - Populations: A few stray individuals and small groups may appear on local lakes and reservoirs in late fall, rarely lingering through early spring. Look for them at Baseline Reservoir, Boulder Reservoir, Marshall Ponds, and Walden Ponds. Pairs nest on muskrat houses or on the banks of prairie lakes and marshes from Nebraska northward into central Canada. - Conservation: Recovering from near-extinction during the early 20th century. About 150,000 were counted in 2012. Photo © 2013 Steve Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998151855-XNJ8T2NGA7ZN3T4W6J5P/tundraswan11.jpg Regional Birds - Tundra Swan (Copy) Tundra Swan - Status: Rare migrant and winter visitor. - Populations: A few stray individuals and small groups may appear on local lakes and reservoirs in late fall, and sometimes a few stick around through early spring. A flock of 15 wintered at Valmont Reservoir in 2012-13. Look for them also at Baseline Reservoir and Boulder Reservoir. Pairs nest on the arctic tundra and winter in the Great Basin and along the West Coast. - Conservation: North American populations have been increasing and now stand at around 200,000. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998240769-N1Z8ZASTM1SULM4KTD5L/woodduck11.jpg Regional Birds - Wood Duck (m) (Copy) Wood Duck (m) - Status: Fairly common summer resident; rare to uncommon in winter. - Populations: Look for nesting pairs along Saint Vrain Creek and Boulder Creek east of the foothills, where females lay eggs in abandoned woodpecker holes and larger tree cavities. In winter, look for the brightly colored males along Boulder Creek near the Boulder Public Library and east of Sawhill Ponds. - Conservation: Wood Ducks have increased throughout much of Colorado as cottonwoods and other deciduous trees have proliferated along streams on the prairie and in the western valleys. North American populations were severely endangered by overhunting during the late nineteenth and early twentieth centuries, but they have recovered impressively. North American populations currently appear to be stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998329229-39SHULGUKQMUDFF5ZK26/woodduck31.jpg Regional Birds - Wood Duck (f) (Copy) Wood Duck (f) - Status: Fairly common summer resident; rare to uncommon in winter. - Populations: Look for nesting pairs along Saint Vrain Creek and Boulder Creek east of the foothills, where females lay eggs in abandoned woodpecker holes and larger tree cavities. In winter, look for the brightly colored males along Boulder Creek near the Boulder Public Library and east of Sawhill Ponds. - Conservation: Wood Ducks have increased throughout much of Colorado as cottonwoods and other deciduous trees have proliferated along streams on the prairie and in the western valleys. North American populations were severely endangered by overhunting during the late nineteenth and early twentieth centuries, but they have recovered impressively. North American populations currently appear to be stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143147437-DG77425FN3JIDZIE795C/NorthernPintailMale.jpg Regional Birds - Northern Pintail (m) (Copy) Northern Pintail (m) - Status: Uncommon to rare summer resident; fairly common migrant and winter resident. - Populations: Small numbers of Northern Pintails mix in with flocks of other dabblers on prairie ponds and reservoirs throughout eastern Colorado. They breed from northern Colorado north through much of Canada to Alaska. Nesting in Boulder County is poorly documented. They winter from British Columbia and New Mexico south to Central America. - Conservation: North American populations approached 10 million during the 1960s, then plummeted to 2-4 million during the drought years of the early 1990s. Numbers appear to be recovering. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143238023-AH7AFGVFWB6P9XGR66CY/NorthernPintailFemale.jpg Regional Birds - Northern Pintail (f) (Copy) Northern Pintail (f) - Status: Uncommon to rare summer resident; fairly common migrant and winter resident. - Populations: Small numbers of Northern Pintails mix in with flocks of other dabblers on prairie ponds and reservoirs throughout eastern Colorado. They breed from northern Colorado north through much of Canada to Alaska. Nesting in Boulder County is poorly documented. They winter from British Columbia and New Mexico south to Central America. - Conservation: North American populations approached 10 million during the 1960s, then plummeted to 2-4 million during the drought years of the early 1990s. Numbers appear to be recovering. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143467349-P0STWV99UVZO44QGFAAT/GreenWingedTealMale.jpg Regional Birds - Green-winged Teal (m) (Copy) Green-winged Teal (m) - Status: Uncommon summer resident; fairly common migrant and winter resident. - Populations: These compact, colorful dabblers nest in river deltas and forest wetlands from Colorado north to central Canada and Alaska. In winter look for them in ice-free streams such as Boulder Creek and Clear Creek. - Conservation: Because most of their breeding areas are far from human activities, these exquisitely-marked teal have been able to maintain relatively high breeding populations of 3-5 million in North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143489132-FOFT67CZY2QES7NT7AYM/GreenWingedTealFemale.jpg Regional Birds - Green-winged Teal (f) (Copy) Green-winged Teal (f) - Status: Uncommon summer resident; fairly common migrant and winter resident. - Populations: These compact, colorful dabblers nest in river deltas and forest wetlands from Colorado north to central Canada and Alaska. In winter look for them in ice-free streams such as Boulder Creek and Clear Creek. - Conservation: Because most of their breeding areas are far from human activities, these exquisitely-marked teal have been able to maintain relatively high breeding populations of 3-5 million in North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143614580-YIYHPCDO3DS3BXP945C2/CanvasbackMale.jpg Regional Birds - Canvasback (m) (Copy) Canvasback (m) - Status: Uncommon to fairly common migrant and winter resident. - Populations: Modest numbers of canvasbacks mix in with flocks of redheads, lesser scaup, and ring-necked ducks, especially during fall and winter. Look for them at Walden Ponds, Valmont Reservoir, and Presbyterian Pond (northeast corner of Valmont and 63rd). They nest from Wyoming north through the Prairie Pothole region to northern Canada and Alaska. Known as the "aristocrats of ducks," these large, elegant divers can reach pond bottoms 30 feet or more below the surface, where they root around for tubers and roots of succulent plants. - Conservation: Declining North American populations during the 1980s landed the species on the Audubon Society "Blue List" of threatened birds, but numbers have recovered since then and most nesting populations seem secure. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143624336-IC9HDBFNPDVAIRHQH3KF/CanvasbackFemale.jpg Regional Birds - Canvasback (f) (Copy) Canvasback (f) - Status: Uncommon to fairly common migrant and winter resident. - Populations: Modest numbers of canvasbacks mix in with flocks of redheads, lesser scaup, and ring-necked ducks, especially during fall and winter. Look for them at Walden Ponds, Valmont Reservoir, and Presbyterian Pond (northeast corner of Valmont and 63rd). They nest from Wyoming north through the Prairie Pothole region to northern Canada and Alaska. Known as the "aristocrats of ducks," these large, elegant divers can reach pond bottoms 30 feet or more below the surface, where they root around for tubers and roots of succulent plants. - Conservation: Declining North American populations during the 1980s landed the species on the Audubon Society "Blue List" of threatened birds, but numbers have recovered since then and most nesting populations seem secure. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998545251-HCNHA1ZZTR91OCKICK8S/redheadduck1.jpg Regional Birds - Redhead Duck (m) (Copy) Redhead Duck (m) - Status: Uncommon summer resident; abundant to fairly common migrant and winter resident. - Populations: Redheads appear by the thousands on prairie lakes and reservoirs throughout eastern Boulder County in October-November and February-March. Walden Ponds and Union Reservoir are particularly good places to see them. They breed primarily in the Prairie Pothole region of the northern plains, but breeding populations also concentrate in California's Central Valley as well as areas of North Texas and Alaska. Breeding has not been documented in Boulder County. - Conservation: Redheads practice "facultative brood parasitism," often laying some or all their eggs in nests of other species. From 1955-2005, North American breeding numbers ranged from 300,000-1,000,000, with no apparent long-range upward or downward trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998622932-O4WJP9IMO2SDE8GL2MT4/ringneckedduck1.jpg Regional Birds - Ring-necked Duck (m) (Copy) Ring-necked Duck (m) - Status: Common migrant; fairly common winter resident; uncommon summer resident. - Populations: Small numbers nest on the shores of mountain ponds surrounded by willow thickets west of the Peak-to-Peak Highway. Long Lake, west of Brainerd Lake, is a good place to see them. Thousands of migrants gather in fall and early spring at prairie lakes and reservoirs, including Sawhill and Walden Ponds, Somberero Marsh, and Pella Crossing. - Conservation: Because nesting pairs require undisturbed willow thickets and ponds, ring-necked ducks are listed as "isolated and restricted" on the Boulder County Birds of Special Concern list. Nesting populations appear to have remained fairly stable since 1980. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998689740-0661FZGQB6NP6VVMNSVN/ringneckedduck2.jpg Regional Birds - Ring-necked Duck (f) (Copy) Ring-necked Duck (f) - Status: Common migrant; fairly common winter resident; uncommon summer resident. - Populations: Small numbers nest on the shores of mountain ponds surrounded by willow thickets west of the Peak-to-Peak Highway. Long Lake, west of Brainerd Lake, is a good place to see them. Thousands of migrants gather in fall and early spring at prairie lakes and reservoirs, including Sawhill and Walden Ponds, Somberero Marsh, and Pella Crossing. - Conservation: Because nesting pairs require undisturbed willow thickets and ponds, ring-necked ducks are listed as "isolated and restricted" on the Boulder County Birds of Special Concern list. Nesting populations appear to have remained fairly stable since 1980. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998780691-INFBLPAK6X8UP0TCR2RX/greaterscaup1.jpg Regional Birds - Greater Scaup (m) (Copy) Greater Scaup (m) - Status: Rare migrant and winter resident. - Populations: A few individuals mix with flocks of other diving ducks on ponds and reservoirs on the plains from November-April. Note the rounded head of males (Lesser Scaup has a subtle notch near the top), with green sheen. Nests in coastal tundra areas of the North American and Siberian Arctic. - Conservation: North American breeding populations number slightly more than a half-million. Global warming may threaten viability of some northern nesting areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998806240-X9ZSSKNHSTZ07DPNMCCM/greaterscaup3.jpg Regional Birds - Greater Scaup (f) (Copy) Greater Scaup (f) - Status: Rare migrant and winter resident. - Populations: A few individuals mix with flocks of other diving ducks on ponds and reservoirs on the plains from November-April. Note the rounded head of males (Lesser Scaup has a subtle notch near the top), with green sheen. Nests in coastal tundra areas of the North American and Siberian Arctic. - Conservation: North American breeding populations number slightly more than a half-million. Global warming may threaten viability of some northern nesting areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591999017159-JH3VFFJWPF7VHDPATP76/LesserScaup1.jpg Regional Birds - Lesser Scaup (m) (Copy) Lesser Scaup (m) - Status: Fairly common migrant and winter resident. - Populations: Look for Lesser Scaups mixed in with flocks of Redheads and Ring-Necked ducks at Walden Ponds, Valmont Reservoir, and Union Reservoir. Millions nest in boreal forests and parklands from Manitoba north and west to central Alaska. Note the slightly notched head of males and purple sheen on the sides of the head. - Conservation: Between 4 million and 8 million individuals were counted annually during 1955-95, making this the most abundant diving duck in North America. Continental populations may have declined recently. Loss of prairie potholes and poisoning from contaminated prey, including zebra mussels, may threaten some populations. Photo © 2013, Stephen Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591999055128-K1YFPYG0N4JOIJT4JSTX/LesserScaup2.jpg Regional Birds - Lesser Scaup (f) (Copy) Lesser Scaup (f) - Status: Fairly common migrant and winter resident. - Populations: Look for Lesser Scaups mixed in with flocks of Redheads and Ring-Necked ducks at Walden Ponds, Valmont Reservoir, and Union Reservoir. Millions nest in boreal forests and parklands from Manitoba north and west to central Alaska. Note the slightly notched head of males and purple sheen on the sides of the head. - Conservation: Between 4 million and 8 million individuals were counted annually during 1955-95, making this the most abundant diving duck in North America. Continental populations may have declined recently. Loss of prairie potholes and poisoning from contaminated prey, including zebra mussels, may threaten some populations. Photo © 2013, Stephen Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000331157-7BWN4Y8ICQZVL63HZ98N/surfscoter1.jpg Regional Birds - Surf Scoter (Copy) Surf Scoter Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000643256-9CK8VFO5ZVUFJ2MOMZ32/longtailedduck3.jpg Regional Birds - Long-tailed Duck (Copy) Long-tailed Duck Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000930138-TJPDB2F99AQZMTVXP4PA/bufflehead1.jpg Regional Birds - Buffelhead (m) (Copy) Buffelhead (m) Bufflehead (m)Item 35 of 261 - Status: Fairly common migrant and winter resident. - Populations: These expert divers frequent gravel ponds and large reservoirs throughout eastern Boulder County from October-May. They nest in tree cavities in boreal forests and aspen parklands of northern Canada and Alaska. - Conservation: Numbers increased markedly from the 1950s to the 1990s, when the North American population exceeded 1 million. Hunters take a substantial toll on migrating flocks. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000974479-VMROX04QEFG8TP8IFR49/bufflehead2.jpg Regional Birds - Buffelhead (f) (Copy) Buffelhead (f) Bufflehead (m)Item 35 of 261 - Status: Fairly common migrant and winter resident. - Populations: These expert divers frequent gravel ponds and large reservoirs throughout eastern Boulder County from October-May. They nest in tree cavities in boreal forests and aspen parklands of northern Canada and Alaska. - Conservation: Numbers increased markedly from the 1950s to the 1990s, when the North American population exceeded 1 million. Hunters take a substantial toll on migrating flocks. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001098101-ZJFTQVBTSH6A2R3RR713/commongoldeneye2.jpg Regional Birds - Common Goldeneye (m) (Copy) Common Goldeneye (m) - Status: Fairly common winter resident; uncommon migrant - Populations: These flashy divers frequent reservoirs and gravel ponds throughout Boulder County, especially during the winter months. They nest in tree cavities in boreal forests and aspen groves throughout most of Canada. Note the oblong (as opposed to crescent-shaped) white spot between the eye and the bill of the male. - Conservation: North American populations appear to be stable, though some nesting areas may be threatened by acidification, deforestation, and removal of potential nesting trees. Hunters kill 60,000-200,000 each winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001143617-UKGGXU52CH6Z8G51GFPZ/commongoldeneye1.jpg Regional Birds - Common Goldeneye (f) (Copy) Common Goldeneye (f) - Status: Fairly common winter resident; uncommon migrant - Populations: These flashy divers frequent reservoirs and gravel ponds throughout Boulder County, especially during the winter months. They nest in tree cavities in boreal forests and aspen groves throughout most of Canada. Note the oblong (as opposed to crescent-shaped) white spot between the eye and the bill of the male. - Conservation: North American populations appear to be stable, though some nesting areas may be threatened by acidification, deforestation, and removal of potential nesting trees. Hunters kill 60,000-200,000 each winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001273906-N5GWJEU2DAWN5B2BY14D/BarrowsGoldeneyeMale.jpg Regional Birds - Barrow's Goldeneye (m) (Copy) Barrow's Goldeneye (m) (Boulder County Extirpated Nesting Populations) - Status: Rare migrant and winter resident. Extirpated nesting species in Boulder County. - Populations: A few wanderers are seen on gravel ponds and reservoirs November-April. Several pairs nest in tree cavities in the Flattops Wilderness, and Denis Gale observed nesting within the Boulder watershed, west of Ward, during the 1880s. Boulder County is at the southern tip of their North American breeding range, which extends up the spine of the Rockies through Canada and into Alaska. - Conservation: Nesting pairs could become reestablished locally if fires or beaver activity created more suitable nesting trees bordering subalpine lakes. About 200,000 individuals inhabit North America, half of them in a single Canadian province. Populations appear to be relatively stable. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001321521-F4E40CZB7AOWJKS0YL14/BarrowsGoldeneyeFemale.jpg Regional Birds - Barrow's Goldeneye (f) (Copy) Barrow's Goldeneye (f) (Boulder County Extirpated Nesting Populations) - Status: Rare migrant and winter resident. Extirpated nesting species in Boulder County. - Populations: A few wanderers are seen on gravel ponds and reservoirs November-April. Several pairs nest in tree cavities in the Flattops Wilderness, and Denis Gale observed nesting within the Boulder watershed, west of Ward, during the 1880s. Boulder County is at the southern tip of their North American breeding range, which extends up the spine of the Rockies through Canada and into Alaska. - Conservation: Nesting pairs could become reestablished locally if fires or beaver activity created more suitable nesting trees bordering subalpine lakes. About 200,000 individuals inhabit North America, half of them in a single Canadian province. Populations appear to be relatively stable. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001430097-C88UFXQUF1KWWY4QKGSF/HoodedMerganserMale.jpg Regional Birds - Hooded Merganser (m) (Copy) Hooded Merganser (m) - Status: Fairly common migrant and winter resident. - Populations: Small groups winter on mid-sized gravel ponds and reservoirs throughout eastern Boulder County. Look for them at Presbyterian Pond (63rd and Valmont) in fall and spring, Baseline Reservoir in late fall, and Sawhill Ponds, fall and spring. As many as 100 may winter on Valmont Reservoir. These cavity-nesters breed in forested regions from the Mississippi River east to the Atlantic Seaboard and in the Northern Rockies and British Columbia. - Conservation: Though nesting pairs may be sensitive to deforestation and acid rain, populations appear to be stable or slightly increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001470932-VJ903LKKPVUAPHE8VDKJ/HoodedMerganserFemale.jpg Regional Birds - Hooded Merganser (f) (Copy) Hooded Merganser (f) - Status: Fairly common migrant and winter resident. - Populations: Small groups winter on mid-sized gravel ponds and reservoirs throughout eastern Boulder County. Look for them at Presbyterian Pond (63rd and Valmont) in fall and spring, Baseline Reservoir in late fall, and Sawhill Ponds, fall and spring. As many as 100 may winter on Valmont Reservoir. These cavity-nesters breed in forested regions from the Mississippi River east to the Atlantic Seaboard and in the Northern Rockies and British Columbia. - Conservation: Though nesting pairs may be sensitive to deforestation and acid rain, populations appear to be stable or slightly increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001595977-MM1AJALJA6AS5ZQYSDTS/CommonMerganserMale.jpg Regional Birds - Common Merganser (m) (Copy) Common Merganser (m) - Status: Uncommon summer resident; common winter resident. - Populations: Large flocks cruise across Baseline Reservoir, Valmont Reservoir, Union Reservoir, and other large bodies of water on the plains, November-April. A few pairs nest in tree cavities or nest boxes on shorelines of gravel pits near Lyons. Colorado is at the southern tip of the North American breeding range, which extends up into Alaska and across forested regions of northern Canada to Labrador. - Conservation: These fish-eaters are particularly vulnerable to pesticides and other contaminants. North American population status is unknown. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001607375-QQR3DNBCJOUM6KDU28D5/CommonMerganserFemale.jpg Regional Birds - Common Merganser (f) (Copy) Common Merganser (f) - Status: Uncommon summer resident; common winter resident. - Populations: Large flocks cruise across Baseline Reservoir, Valmont Reservoir, Union Reservoir, and other large bodies of water on the plains, November-April. A few pairs nest in tree cavities or nest boxes on shorelines of gravel pits near Lyons. Colorado is at the southern tip of the North American breeding range, which extends up into Alaska and across forested regions of northern Canada to Labrador. - Conservation: These fish-eaters are particularly vulnerable to pesticides and other contaminants. North American population status is unknown. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001703934-OBEQQ38NZQ6LKRYTWSQB/RedBreastedMerganser.jpg Regional Birds - Red-breasted Merganser (Copy) Red-breasted Merganser - Status: Fairly common migrant and winter resident. - Populations: Look for small and scattered flocks mixed in with larger flocks of Common Mergansers on Valmont Reservoir, Baseline Reservoir, and Union Reservoir, October-April. These ground-nesting mergansers breed in northern boreal forests and the Arctic tundra from Alaska clear across the continent to Labrador, Baffin Island, and Greenland. - Conservation: While numbers declined steeply during the first two-thirds of the twentieth century, they appear to have recovered somewhat during the past two decades. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001803572-HJ7VRIYIHAM2DUYO56PP/RuddyDuckMale.jpg Regional Birds - Ruddy Duck (m) (Copy) Ruddy Duck (m) - Status: Uncommon summer resident; fairly common migrant and rare winter resident. - Populations: Small numbers appear on Boulder County gravel ponds and reservoirs during spring and fall migration. Though some stay throughout the summer and pairs have nested throughout the plains and mountain parks of Colorado, nesting has not been clearly documented in Boulder County. Ruddy Ducks nest all the way from southern Mexico to northern Canada, especially in grassland areas, with the largest nesting concentrations occurring in the Prairie Pothole region. - Conservation: North American populations appear to be stable or increasing. Ruddy Ducks have been introduced to Europe, where they are disdained by hunters and considered a pest by others. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001818144-KPTWSHBGNLJIBG9XV6A5/RuddyDuckFemale.jpg Regional Birds - Ruddy Duck (f) (Copy) Ruddy Duck (f) - Status: Uncommon summer resident; fairly common migrant and rare winter resident. - Populations: Small numbers appear on Boulder County gravel ponds and reservoirs during spring and fall migration. Though some stay throughout the summer and pairs have nested throughout the plains and mountain parks of Colorado, nesting has not been clearly documented in Boulder County. Ruddy Ducks nest all the way from southern Mexico to northern Canada, especially in grassland areas, with the largest nesting concentrations occurring in the Prairie Pothole region. - Conservation: North American populations appear to be stable or increasing. Ruddy Ducks have been introduced to Europe, where they are disdained by hunters and considered a pest by others. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773187012-9LY7J3QA9X96HQ07QTE0/image-asset.jpeg Regional Birds - Ring-necked Pheasant (m) (Copy) Ring-necked Pheasant (m) - Status: Uncommon year-round resident. - Populations: Pheasants have been introduced periodically to our area by game clubs, and their numbers rise and fall depending on the severity of our winters. Recent reports have come from rural areas east of Boulder, around Louisville, and east and south of Longmont. - Conservation: Pheasants were introduced to North America from Eurasia and have proliferated in rural areas, especially in the eastern half of the continent. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773657754-VVKE6DXMQJ695GMNW6B7/image-asset.jpeg Regional Birds - White-tailed Ptarmigan (summer plumage) (Copy) White-tailed Ptarmigan (summer plumage) - Status: Uncommon year-round resident in the alpine tundra and krumholz region, generally above 11,000 feet. - Populations: North America's southernmost ptarmigan species nests from New Mexico north to southeastern Alaska. Physical adaptations, including feathered feet and eyelids, enable them to survive alpine winters. Look for them in the Indian Peaks Wilderness above tree line in summer and at the interface between the upper forest and the alpine tundra in winter. - Conservation: Global warming will eventually shrink the area of white-tailed ptarmigan habitat, forcing the birds northward. Road and ski area construction in the high mountains probably limits and fragments nesting habitat. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773761186-TQ9VLD0DE7DO58BI0SVN/image-asset.jpeg Regional Birds - White-tailed Ptarmigan (winter plumage) (Copy) White-tailed Ptarmigan (winter plumage) - Status: Uncommon year-round resident in the alpine tundra and krumholz region, generally above 11,000 feet. - Populations: North America's southernmost ptarmigan species nests from New Mexico north to southeastern Alaska. Physical adaptations, including feathered feet and eyelids, enable them to survive alpine winters. Look for them in the Indian Peaks Wilderness above tree line in summer and at the interface between the upper forest and the alpine tundra in winter. - Conservation: Global warming will eventually shrink the area of white-tailed ptarmigan habitat, forcing the birds northward. Road and ski area construction in the high mountains probably limits and fragments nesting habitat. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588816045733-DJX7BQOPML1HND8G0VVO/image-asset.jpeg Regional Birds - Dusky Grouse (Copy) Dusky Grouse - Status: Uncommon year-round resident. - Populations: These secretive grouse inhabit Boulder County conifer forests from 6000-11,500 feet. In spring you can hear the males "drumming" with their wings (a soft, hollow-sounding series of hoots) from the Boulder Mountain Park to the Indian Peaks Wilderness. Females lay their eggs on the ground, and young fledge shortly after hatching. - Conservation: Recreational pressures in the foothills appear to be pushing dusky grouse farther up into the mountains. Roaming dogs and feral cats, along with urban-adapted predators such as coyote and raccoon, may predate nests. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588816128260-26PMQZDEXLANPQETNIKD/image-asset.jpeg Regional Birds - Wild Turkey (Copy) Wild Turkey - Status: Fairly common year-round resident in the foothills; uncommon year-round resident on the plains. - Populations: Flocks of wild turkeys roam through ponderosa pine woodlands in the lower foothills throughout the year. Look for them at Heil Ranch, Hall Ranch, Walker Ranch, and on the flanks of Eldorado Mountain. Turkeys also skulk through shrubby areas adjacent to prairie streams, including North Saint Vrain Creek and Boulder Creek. - Conservation: Largely as a result of reintroduction programs initiated during the 1960s, the North American wild turkey population has ballooned to more than 7 million. Turkeys now commonly strut down side streets of many prairie towns. Populations in Boulder County have increased dramatically during the past two decades. It's not known whether Wild Turkeys are native to Boulder County. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889290070-8J3SSKIM11T7EB4B7VMH/image-asset.jpeg Regional Birds - Common Loon (Copy) Common Loon - Status: Uncommon to rare spring and fall migrant on the plains, usually at large reservoirs. - Populations: A few migrating Common Loons are observed each fall and spring on Valmont Reservoir, Baseline Reservoir, Boulder Reservoir, or other large bodies of water on the plains. They nest from Montana and the Great Lakes northward to Alaska and Baffin Island. - Conservation: Birds of North America described North American breeding populations as "robust," with approximately a quarter of a million nesting pairs. However, breeding pairs are regionally threatened by fluctuating water levels in reservoirs, nest disturbance by recreational users, chemicals, and possibly, global warming. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889366047-BMPZUK43NRO0FNHHKR4P/image-asset.jpeg Regional Birds - Pied-billed Grebe (Copy) Pied-billed Grebe - Status: Fairly common summer resident in wetlands on the plains. Uncommon to fairly common year-round reservoir on the plains. - Populations: Though often seen and heard on the plains during the summer breeding season, nesting is rarely documented in Boulder County. Likely nesting locations include Sawhill and Walden ponds wildlife areas and South Boulder Creek State Natural Area. Male’s booming voice, a rhythmic series of gulping and cooing notes, may reveal nesting territories. - Conservation: North American nesting populations appear to be fairly stable, though disturbance of wetlands in some regions has led to significant declines in numbers of successful nests. In Colorado Pied-Billed Grebes became much more common during the twentieth century as reservoirs were constructed and marshlands created. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889464028-92LP0PU61MA0EKTFBDW7/image-asset.jpeg Regional Birds - Horned Grebe (Copy) Horned Grebe - Status: Fairly common migrant on the plains during spring and fall. Breeds from northern plains to Alaska and Hudson's Bay. - Populations: Small to large flocks are observed regularly in spring and fall on Baseline Reservoir, Valmont Reservoir, Union Reservoir, Boulder Reservoir, Sombrero Marsh, and at Coot Lake. Best distinguished from Eared Grebe by bill and head shape, along with details of head patterns. - Conservation: Though one of the most abundant breeding grebes in North America, its breeding range appears to be contracting to the northwest, and biologists are not sure why. Potential threats include pesticides, degradation of marsh nesting habitat, and mortality from fishing nets. Photo © 2014, PHOTOGRAPHER https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889556408-IL3GKI6CVRXOXFK06OB9/image-asset.jpeg Regional Birds - Horned Grebe (breeding) (Copy) Horned Grebe (breeding) - Status: Fairly common migrant on the plains during spring and fall. Breeds from northern plains to Alaska and Hudson's Bay. - Populations: Small to large flocks are observed regularly in spring and fall on Baseline Reservoir, Valmont Reservoir, Union Reservoir, Boulder Reservoir, Sombrero Marsh, and at Coot Lake. Best distinguished from Eared Grebe by bill and head shape, along with details of head patterns. - Conservation: Though one of the most abundant breeding grebes in North America, its breeding range appears to be contracting to the northwest, and biologists are not sure why. Potential threats include pesticides, degradation of marsh nesting habitat, and mortality from fishing nets. Photo © 2014, PHOTOGRAPHER https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889610116-MS2BGL6DQTTB43I9D8V9/image-asset.jpeg Regional Birds - Eared Grebe (Copy) Eared Grebe (Boulder County rare and declining nesting populations) - Status: Uncommon to fairly common spring and fall migrant on ponds and reservoirs throughout the plains. Nesting was documented in Boulder County prior to 1900, and pairs have nested recently at Union Reservoir, just east of Boulder County. - Populations: Small flocks appear in April and May, and again throughout the fall, at Coot Lake, Boulder Reservoir, Baseline Reservoir, and other large bodies of water on the plains. Pairs build floating nests in shallow water from the Texas Panhandle north to the prairie pothole region of southern Canada. - Conservation: Eared Grebes were heavily hunted for their soft feathers, which were used in the millinery trade, and their pickled eggs were sold throughout North America during the early 20th century. Populations have since rebounded and appear to be fairly stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592144128761-O2LV80X4OA2H4J083JVE/EaredGrebeWinter.jpg Regional Birds - Eared Grebe (winter) (Copy) Eared Grebe (winter) (Boulder County rare and declining nesting populations) - Status: Uncommon to fairly common spring and fall migrant on ponds and reservoirs throughout the plains. Nesting was documented in Boulder County prior to 1900, and pairs have nested recently at Union Reservoir, just east of Boulder County. - Populations: Small flocks appear in April and May, and again throughout the fall, at Coot Lake, Boulder Reservoir, Baseline Reservoir, and other large bodies of water on the plains. Pairs build floating nests in shallow water from the Texas Panhandle north to the prairie pothole region of southern Canada. - Conservation: Eared Grebes were heavily hunted for their soft feathers, which were used in the millinery trade, and their pickled eggs were sold throughout North America during the early 20th century. Populations have since rebounded and appear to be fairly stable. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889816160-BVV33OU9LML84A2YTIUG/image-asset.jpeg Regional Birds - Western Grebe (Copy) Western Grebe - Status: Fairly common to common migrant and summer resident on large reservoirs on the plains. Nesting has not been documented in Boulder County. - Populations: Flocks of several hundred Western Grebes may appear on our larger reservoirs during spring and fall migration. Nesting has been documented in neighboring Weld County and throughout much of northern Colorado, and in May these large and attractive grebes perform their spectacular, "running on water," courtship displays on local reservoirs. Up to 100 pairs have nested at Eleven Mile Reservoir in South Park, where they lay their eggs in floating nests located far from shore. - Conservation: This species has become much more common in Colorado with the construction of reservoirs to irrigate farmlands, but fluctuating water levels in reservoirs makes nesting a risky proposition. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889894118-7LNAJAQ7TTHL902BHQ0K/image-asset.jpeg Regional Birds - Clark's Grebe (Copy) Clark's Grebe - Status: Fairly common to common migrant and summer resident on large reservoirs on the plains. Nesting has not been documented in Boulder County. - Populations: Flocks of several hundred Western Grebes may appear on our larger reservoirs during spring and fall migration. Nesting has been documented in neighboring Weld County and throughout much of northern Colorado, and in May these large and attractive grebes perform their spectacular, "running on water," courtship displays on local reservoirs. Up to 100 pairs have nested at Eleven Mile Reservoir in South Park, where they lay their eggs in floating nests located far from shore. - Conservation: This species has become much more common in Colorado with the construction of reservoirs to irrigate farmlands, but fluctuating water levels in reservoirs makes nesting a risky proposition. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889966224-4WZFR7MO5C1MQKK1SQSI/image-asset.jpeg Regional Birds - Double-crested Cormorant (Copy) Double-crested Cormorant - Status: Fairly common year-round resident, with highest numbers usually reported during summer. - Populations: Double-crested Cormorants nest in heronries in eastern Boulder County and overwinter at Valmont Reservoir. Numbers have increased dramatically in recent years, partially due to existence of open water throughout the winter and possibly due to proliferation of heronries throughout Boulder County. - Conservation: Local protection of breeding sites, the 1972 ban on DDT, and continuing construction of reservoirs has contributed to increasing populations throughout their extensive breeding range, which extends from Alaska and Baja California westward across the western deserts, central plains, and Great Lakes to Newfoundland and Florida. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588890181659-3FAOP4XLLQ84HS895IRL/image-asset.jpeg Regional Birds - American White Pelican (Copy) American White Pelican - Status: Fairly common to common migrant and summer resident. Nesting has not been documented in Boulder County. - Populations: American White Pelicans nest at three known locations in Colorado--Riverside Reservoir East of Greeley, Antero Reservoir in South Park, and McFarlane Reservoir in North Park--and only three dozen locations in all of North America. The largest colony, at Chase Lake in North Dakota, has supported tens of thousands of breeding pairs. Adults may fly 30 miles or more away from nesting colonies to fish. - Conservation: American White Pelican populations increased dramatically after DDT was banned in 1972. North American Breeding Bird Survey data indicate an increase of about 2.5% per year from 1981-2011. Varying water levels in reservoirs, along with predation by carnivores, result in dramatic variations in breeding colony sizes. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588994504540-5HTIP6NH70NSRSDEM1L1/image-asset.jpeg Regional Birds - American Bittern (Copy) American Bittern (Boulder County isolated or restricted) - Status: Uncommon summer resident. Nesting has been documented at a dozen wetland locations on the plains of Boulder County. - Populations: American Bitterns nest in cattail marshes at Boulder Reservoir, Coot Lake, Boulder Valley Ranch, Sawhill and Walden Ponds, White Rocks, and South Boulder Creek State Natural Area. Their ground nests are preyed upon by coyotes, raccoons, and bullsnakes. Males are easily identified by their eerie "oonk-a-loonk" calls, reminiscent of the sound of a hand-operated water pump. - Conservation: Disturbance of marshes throughout Colorado led to this species being listed as high-priority special concern by the Colorado Natural Heritage Program. North American Breeding Bird Survey routes show a 0.6% per year decline throughout North America from 1966-2011. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588994925565-Y82XP1BKIT4MD17TGFL7/image-asset.jpeg Regional Birds - Great Blue Heron (Copy) Great Blue Heron - Status: Common summer resident and fairly common winter resident, primarily on the plains. - Populations: Throughout the 20th and early 21st centuries, Great Blue Herons nested in one large heronry in Boulder County, first at Crane Hollow, then at Sawhill Ponds, and finally along Boulder Creek east of 95th Street. This latter heronry, the largest in Colorado, was abandoned recently after most of the cottonwoods used for nesting died. New heronries have sprung up at Crane Hollow, Hygiene, Walden Ponds, and Boulder Reservoir. - Conservation: This highly-adaptive generalist appears to be thriving throughout its North American breeding range, which extends from Baja California north to Alaska and Nova Scotia. The North American Breeding Bird Survey documented a 1.2% per year increase in U.S. numbers from 1966-2011. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995095982-YONZQ1SW9CEN5AOVQHEQ/image-asset.jpeg Regional Birds - Great Egret (Copy) Great Egret (Boulder County Rare and Isolated) - Status: Fairly common summer resident. Nests just east of Boulder County in a large heronry at Saint Vrain State Park. - Populations: These large white herons fish throughout the summer on the shores of Union Reservoir, Boulder Reservoir, and Walden Ponds. They nest with other herons in cottonwood groves. They were reported nesting in only two Colorado locations during the first Colorado Breeding Bird Atlas project. - Conservation: North American Breeding Bird Survey data indicates a 2.5% per year increase in numbers from 1966-2011. Here in Colorado, a couple of new nesting colonies have sprouted up during the past two decades. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995217821-UZFO2JWQS5DQOEQCDN9S/image-asset.jpeg Regional Birds - Snowy Egret (Copy) Snowy Egret (Boulder County Rare and Isolated) - Status: Fairly common summer resident. Nests just east of Boulder County in a large heronry at Saint Vrain State Park. - Populations: These large white herons fish throughout the summer on the shores of Union Reservoir, Boulder Reservoir, and Walden Ponds. They nest with other herons in cottonwood groves. They were reported nesting in only two Colorado locations during the first Colorado Breeding Bird Atlas project. - Conservation: North American Breeding Bird Survey data indicates a 2.5% per year increase in numbers from 1966-2011. Here in Colorado, a couple of new nesting colonies have sprouted up during the past two decades. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995325189-6OCFCU9KLVFGGE8LPA0H/image-asset.jpeg Regional Birds - Green Heron (Copy) Green Heron - Status: Boulder County Isolated. Uncommon to rare summer resident. Nesting has not been reported recently in Boulder County. - Populations: Green Herons breed in a variety of wetland types, including shorelines of rivers, lakes, and reservoirs, as well as freshwater marshes and swamps. Nesting has been reported at a half dozen wetland locations at the base of the Front Range foothills, including two locations in West Denver. - Conservation: Highest North American nesting concentrations occur in mangrove thickets along the southeastern U.S. coast, where dense, tangled vegetation, facilitates nest concealment and defense. Here in more arid Colorado, anecdotal records suggest that numbers have increased slightly since the early 1900s. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588996157734-530E485VH6KMJZ6VXRKN/image-asset.jpeg Regional Birds - Black-crowned Night Heron (Copy) Black-crowned Night Heron - Status: Boulder County Isolated. Uncommon to rare summer resident. Nesting has not been reported recently in Boulder County. - Populations: Green Herons breed in a variety of wetland types, including shorelines of rivers, lakes, and reservoirs, as well as freshwater marshes and swamps. Nesting has been reported at a half dozen wetland locations at the base of the Front Range foothills, including two locations in West Denver. - Conservation: Highest North American nesting concentrations occur in mangrove thickets along the southeastern U.S. coast, where dense, tangled vegetation, facilitates nest concealment and defense. Here in more arid Colorado, anecdotal records suggest that numbers have increased slightly since the early 1900s. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995583637-3S1NMPG0PRD21IQXFB0B/image-asset.jpeg Regional Birds - White-faced Ibis (Copy) White-faced Ibis - Status: Fairly common spring migrant. Uncommon to rare summer resident and fall migrant. Nesting has not been documented in Boulder County. - Populations: These long-beaked, exotic-appearing herons nest in freshwater marshes in scattered areas of Colorado, primarily in the San Luis Valley and on the Western Slope. Flocks of 50-100 frequent Boulder County marshes and shorelines in May, especially around Boulder Reservoir and Sawhill and Walden Ponds. - Conservation: Since nesting Ibis are extremely sensitive to rising and falling water levels, breeding numbers fluctuate dramatically from year to year. In the San Luis Valley, where as many as 500 pairs have nested during some years, nest productivity is constrained by overgrazing, human disturbance, and predation by corvids and raccoons. Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995641061-CHOC136I5LXEBHPVZAEW/image-asset.jpeg Regional Birds - White-faced Ibis (winter) (Copy) White-faced Ibis (winter) - Status: Fairly common spring migrant. Uncommon to rare summer resident and fall migrant. Nesting has not been documented in Boulder County. - Populations: These long-beaked, exotic-appearing herons nest in freshwater marshes in scattered areas of Colorado, primarily in the San Luis Valley and on the Western Slope. Flocks of 50-100 frequent Boulder County marshes and shorelines in May, especially around Boulder Reservoir and Sawhill and Walden Ponds. - Conservation: Since nesting Ibis are extremely sensitive to rising and falling water levels, breeding numbers fluctuate dramatically from year to year. In the San Luis Valley, where as many as 500 pairs have nested during some years, nest productivity is constrained by overgrazing, human disturbance, and predation by corvids and raccoons. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145057240-JUW4AB6YCDBQWBFR1J7U/TurkeyVulture.jpg Regional Birds - Turkey Vulture (Copy) Turkey Vulture - Status: Common summer resident and spring and fall migrant. - Populations: Pairs nest in remote caves and crevices in the Flatirons rock formation and foothills canyons. They are so secretive that only three nests have actually been documented in Boulder County. However, as many as 40 non-breeding Turkey Vultures gather in treetop roosts near 4th and University in west Boulder each summer. - Conservation: These adaptive vultures take advantage of road kills and garbage dumps, and their numbers appear to be increasing throughout much of North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145140790-ODI4UQ7FCANADLX3AKBF/Osprey.jpg Regional Birds - Osprey (Copy) Osprey (Boulder County isolated or restricted) - Status: Fairly common summer resident and migrant, with a half dozen pairs nesting within the county. - Populations: Pairs nest primarily on artificial nest platforms near prairie reservoirs, including Boulder Reservoir, where 3-4 pairs nest, Longmont Fairgrounds ponds, and Sawhill Ponds. Ospreys nested historically in the mountains of Boulder County, and a pair still nests beside a beaver pond just south of the county line near Rollinsville. - Conservation: Populations have increased dramatically in North America since the banning of DDT in 1972. Boulder County populations continue to increase. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145272662-0IWIGKABTMOONHJOL83M/BaldEagle.jpg Regional Birds - Bald Eagle (Copy) Bald Eagle (Boulder County isolated or restricted) - Status: Uncommon summer resident; fairly common winter resident. - Populations: Bald Eagles were first observed nesting in Boulder County in 2002, and 6 pairs nested in 2013. Nests are placed primarily in cottonwoods in riparian areas closed off to human access. Winter populations gather around prairie dog colonies, where they snatch captured prairie dogs from hawks, and also cruise rural areas looking for road-killed deer. - Conservation: Bald Eagle numbers have increased dramatically throughout North America since the banning of DDT in 1972. Construction of reservoirs on the plains of Boulder County has enhanced nesting opportunities here, as has the recent proliferation of road-killed deer. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145423401-EBINXSD0O303CM7TFWV7/NorthernHarrier.jpg Regional Birds - Northern Harrier (Copy) Northern Harrier (Boulder County rare and declining nesting populations; isolated) - Status: Rare summer resident; fairly common winter resident. - Populations: Northern Harriers nest primarily in cattail marshes and sedge/rush wetlands on the plains. The only successful Boulder County nests since 1980 have been at wetlands west of Boulder Reservoir and Coot Lake. Harriers are frequently seen in fall and winter as they course low over marshes and grasslands listening for scurrying meadow voles. - Conservation: Once considered a fairly common breeding species in Boulder County, Northern Harrier is now probably our most endangered nesting bird. Successful nesting has been observed only four times during the past 10 years. North American populations are also declining. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145508866-L8LHUS2O5J2WZQ03UYPM/SharpShinnedHawk.jpg Regional Birds - Sharp-shinned Hawk (Copy) Sharp-shinned Hawk - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: These small, agile accipiters nest in dense conifer forests from the foothills to the subalpine. Nests are concealed among crowded boughs and are most easily located by listening for the screams of the aggressive adults. Migrating sharpies stream over the foothills throughout April and September. - Conservation: While both the North American Breeding Bird Survey and some hawk migration counts have noted declines in the number of Sharp-shinned Hawks observed, the data are not reliable enough to confirm a clear trend. In Boulder County, maturation of Douglas-fir forests has probably benefited nesting populations. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145604652-3PIXAXAVET8XHU1RX0QW/CoopersHawk.jpg Regional Birds - Cooper's Hawk (Copy) Cooper's Hawk - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: Once thought to nest almost exclusively in crowded conifer forests, Cooper's Hawks have recently taken to Boulder County urban areas, including Boulder, Longmont, Louisville, and Lafayette, where they nest in deciduous trees. Pairs still nest in the mountains from the foothills to the subalpine and thousands stream over our hogback ridges during April and September migration. - Conservation: This species has made a dramatic change in its nesting habits during the last couple of decades. Once thought to nest almost exclusively in Boulder County conifer forests, Cooper's Hawks now frequently nest in towns on the plains. No reliable data exists concerning local population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145681002-6U462ZJAE1BXMOON1VCB/CoopersHawkJuvenile.jpg Regional Birds - Cooper's Hawk (juvenile) (Copy) Cooper's Hawk (juvenile) - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: Once thought to nest almost exclusively in crowded conifer forests, Cooper's Hawks have recently taken to Boulder County urban areas, including Boulder, Longmont, Louisville, and Lafayette, where they nest in deciduous trees. Pairs still nest in the mountains from the foothills to the subalpine and thousands stream over our hogback ridges during April and September migration. - Conservation: This species has made a dramatic change in its nesting habits during the last couple of decades. Once thought to nest almost exclusively in Boulder County conifer forests, Cooper's Hawks now frequently nest in towns on the plains. No reliable data exists concerning local population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145757944-3MDFVQ9ZVH5AALWKALT6/NorthernGoshawk.jpg Regional Birds - Northern Goshawk (Copy) Northern Goshawk (Boulder County isolated or restricted) - Status: Uncommon year-round resident. - Populations: These secretive and aggressive accipiters nest in tall conifers and aspen groves from the upper foothills to the high subalpine, where they hunt squirrels, mice, and songbirds. A pair has nested recently in a remote area of Heil Ranch Open Space, northwest of Boulder, and several pairs nest in Rocky Mountain National Park and the Indian Peaks Wilderness. - Conservation: During the late 1990s and early 2000s, several pairs nested in the Mountain Park and adjacent foothills west of Boulder. No nests have been detected in this area for several years. This reclusive hawk appears to be particularly sensitive to intrusion into nesting areas by recreational users. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145838247-LBXMQGSEH8P8FK9OKR8I/SwainsonsHawk.jpg Regional Birds - Swainson's Hawk (Copy) Swainson's Hawk - Status: Fairly common summer resident. - Populations: Swainson's hawks fly up from Argentina in flocks often numbering several hundred. They nested historically on the prairies of eastern Boulder County, but with many of those areas invaded by trees and Red-tailed Hawks, some pairs have taken to urban open space areas. At least seven pairs nested within the city limits of Broomfield in 2012. - Conservation: Poisoning by insecticides used to control grasshoppers killed tens of thousands of Swainson's Hawks in Argentina during the first decade of this century. Fragmentation of prairies by urbanization and tree invasion has reduced nesting habitat throughout North America. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145989105-SXLZGMW3MVTKXEGQOZQX/RedTailedHawk.jpg Regional Birds - Red-tailed Hawk (Copy) Red-tailed Hawk - Status: Common year-round resident. - Populations: This suburban-adapted generalist nests throughout Boulder County, from the plains to the subalpine. Pairs stake out nesting territories wherever there are groves of cottonwoods or other trees and prey on virtually anything that moves, including rodents, birds, and snakes. - Conservation: Numbers of wintering Red-tailed Hawks doubled in Boulder County from 1990-2013, and summer resident populations have probably increased as well. These generalists tend to outcompete other hawks near human settlements. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146060917-2MIJP4U96VVLWTE7VHU7/FerruginousHawk.jpg Regional Birds - Ferruginous Hawk (Copy) Ferruginous Hawk - Status: Uncommon winter resident. No nesting has been documented in Boulder County. - Populations: This largest and most regal of North American hawks inhabits prairies and deserts, where it preys on large rodents, including rabbits and prairie dogs. Wintering Ferruginous Hawks gather around prairie dog colonies in northern Boulder County. Look for them around Lagerman Reservoir and at Rabbit Mountain. - Conservation: Fairly common in winter here during the 1980s and early 1990s, Ferruginous Hawk numbers have plummeted as our remaining prairies have been fragmented by non-native trees and expanding towns. North American numbers remained fairly stable from 1966-2011. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146140388-E5R28P80C1X103SF2E96/RoughLeggedHawk.jpg Regional Birds - Rough-legged Hawk (Copy) Rough-legged Hawk - Status: Uncommon winter resident on the plains. - Populations: These large, small-taloned hawks nest on the arctic plain, where they prey on small mammals. They winter as far south as California, New Mexico, and Texas. In Boulder County look for them in areas of open grasslands interspersed with wetlands. - Conservation: Numbers observed in winter in Boulder County have declined more than 90% since the early 1990s. Warming temperatures on the plains may be enabling wintering populations to shift farther north; fragmentation of native grasslands and wetlands on the plains of Boulder County may discourage these open country hawks from settling in here during the winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146208514-KMLNPS963SPQ98C3RMQ9/GoldenEagle.jpg Regional Birds - Golden Eagle (Copy) Golden Eagle - Status: Fairly common year-round resident. Nests on cliff faces from the lower foothills to the high mountains. - Populations: About 15-20 Golden Eagle pairs nest in Boulder County, constructing their nests on sheer cliffs or occasionally tall trees, especially in the foothills. One nest on the Lefthand Palisades, North of Boulder, has been continuously active since 1885. Golden Eagles range out onto the plains to hunt cottontails, prairie dogs, and other rodents, and many defend foraging territories year-round. - Conservation: North American Breeding Bird Survey data indicate a decline in Golden Eagle numbers throughout North America from 1966-2011. Many are killed by automobiles as they scavenge road-killed prey, and others by collisions with power lines and windmills. Disturbance of cliff nesting habitats remains a concern. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146276982-XHHDFAN347SOVM1PN37T/AmericanKestrel.jpg Regional Birds - American Kestrel (Copy) American Kestrel - Status: Common year-round resident. - Populations: These small, colorful falcons nest in woodpecker holes throughout most of Boulder County, including towns on the plains. They prey on small rodents, birds, and insects, especially grasshoppers. - Conservation: Since American Kestrels thrive in urban environments, numbers have increased throughout much of North America. Numbers detected on Boulder County wintering raptor surveys have doubled since 1990. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146342588-JUM6MYOMKKPXN8E1MJNA/PeregrineFalcon.jpg Regional Birds - Peregrine Falcon (Copy) Peregrine Falcon (Boulder County rare; isolated or restricted) - Status: Uncommon summer resident; rare spring and fall migrant. - Populations: Fewer than a half-dozen pairs nest on cliff faces, primarily in the foothills, and fly out onto the plains to hunt waterfowl and rodents. Two of the nesting sites are in the Boulder Mountain Park, just southwest of town. - Conservation: After being nearly extirpated throughout North America by DDT poisoning, Peregrine Falcons have bounced back, and North American populations have increased fairly steadily since the early 1970s. They compete with Prairie Falcons and can displace them from nesting sites. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146421627-FG5LB0K90JZKAEFXCKOY/PrairieFalcon.jpg Regional Birds - Prairie Falcon (Copy) Prairie Falcon (Boulder County isolated or restricted) - Status: Uncommon year-round resident. - Populations: A half-dozen or more pairs nest on cliff faces, primarily in the foothills, but cliff nests have been recorded as high as 11,500 feet in Rocky Mountain National Park. Nesting adults fly out onto the plains where they hunt rodents and birds. Look for them perching on telephone poles or bare tree limbs in areas of shortgrass prairie. - Conservation: Nesting numbers in Boulder County appear to have remained steady from 1982-2013, based on annual nest monitoring by Boulder County Nature Association and local parks volunteers. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158186770-PJNQ7D4E9S9BFB3CI6YI/VirginiaRail.jpg Regional Birds - Virginia Rail (Copy) Virginia Rail - Status: Uncommon year-round resident. - Populations: These secretive rails nest in cattail marshes from the plains of Boulder County up into the montane parklands. They are best identified by their harsh, "ki-dik, ki-dik, ki-dik," calls, given throughout the spring and summer on nesting territories. Listen for them at Sawhill Ponds and in the wetlands west of Boulder Reservoir. - Conservation: Numbers have diminished in areas where farmlands have replaced freshwater marshes. North American Breeding Bird Survey results indicate a steady decline in populations from 1966-2011. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158198547-ZZN3ZCI6J9409KCDHOYX/Sora.jpg Regional Birds - Sora (Copy) Sora - Status: Uncommon summer resident. - Populations: Soras nest in a variety of wetlands, especially cattail marshes on the plains. Listen for their descending "whump- whump- whump- whump- whump- whump-sploosh" calls at Sawhill Ponds and in the wetlands west of Boulder Reservoir, as well as in montane wetlands. - Conservation: This is the most abundant and widely distributed rail in North America, and little if any range contraction has been noted. However, due to the secretive nature of Soras, little is known about their population status. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158207878-X5UFA2ZFJ0U4BS0E6UTK/AmericanCoot.jpg Regional Birds - American Coot (Copy) American Coot - Status: Common year-round resident. - Populations: American Coots nest in a variety of wetlands, preferring marshes with tall emergent vegetation. In Boulder County they nest around reservoirs and in freshwater marshes up to about 8000 feet. - Conservation: Numbers appear to be fairly stable in Colorado and throughout their North American breeding range. Draining of wetlands is always a threat, though these adaptive birds seem to do well in a variety of wetland habitats. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158226612-AJLQ89QY58NLFJC9VVN2/SandhillCrane.jpg Regional Birds - Sandhill Crane (Copy) Sandhill Crane - Status: Uncommon fall migrant; rare spring migrant. - Populations: Sandhill Cranes nest from western Colorado and western Nebraska north to arctic Canada, Alaska, and Siberia. The flocks that fly through Boulder County each October consist mostly of Greater Sandhill Cranes headed for wintering areas in Arizona, New Mexico, and West Texas. - Conservation: Both Greater Sandhill Crane (around 120,000) and Lesser Sandhill Crane (around 600,000) numbers continue to grow, and breeding ranges are slowly expanding. More than half a million Sandhill Cranes gather along the Platte River in Western Nebraska each spring during March-April migration. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159101595-FRJ8YG6XVTN0QC4S0X9B/Killdeer.jpg Regional Birds - Killdeer (Copy) Killdeer - Status: Very common summer resident; uncommon winter resident. - Populations: This shorebird conceals its speckled eggs on bare ground and has adapted readily to gravel parking lots, construction sites, and agricultural fields. Look for Killdeers on the plains wherever there is bare or disturbed ground near wetlands or bodies of water. - Conservation: Literally considered the least endangered bird in Colorado on the Colorado Priorities 1995 list, since it seems to thrive in human-disturbed environments. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159111956-CQAEQBMC5WHIKPXECILJ/BlackNeckedStilt.jpg Regional Birds - Black-necked Stilt (Copy) Black-necked Stilt - Status: Rare migrant. - Populations: These elegant shorebirds nest in scattered locations of eastern and central Colorado, with the largest numbers occurring in the San Luis Valley. In Boulder County, look for them in April and May foraging in shallow water and mud flats around our prairie reservoirs and ponds. Several pairs have nested at Lower Latham Reservoir, in Weld County. - Conservation: Fewer than 500 pairs nest in Colorado. Throughout North America, Breeding Bird Survey results suggest a statistically significant increase in numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159153092-A6NKJYK12BH2JLVUVRW4/AmericanAvocet.jpg Regional Birds - American Avocet (Copy) American Avocet - Status: STATUS - Populations: Look for migrating and a few nesting avocets in shallow, often brackish water on the plains, where they sweep their upcurved bills like pendulums through the brine. Pairs nest in loose colonies, placing their flimsy nests in simple scrapes on mud flats. - Conservation: Colorado nesting range appears to have gradually expanded since the late 19th century, with the largest concentrations occurring in the San Luis Valley. North American Breeding Bird Survey data indicate a modest decline in overall numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159163383-0XX7A5KI2ROJZRDWKPLD/AmericanAvocetWinter.jpg Regional Birds - American Avocet (winter) (Copy) American Avocet (winter) - Status: STATUS - Populations: Look for migrating and a few nesting avocets in shallow, often brackish water on the plains, where they sweep their upcurved bills like pendulums through the brine. Pairs nest in loose colonies, placing their flimsy nests in simple scrapes on mud flats. - Conservation: Colorado nesting range appears to have gradually expanded since the late 19th century, with the largest concentrations occurring in the San Luis Valley. North American Breeding Bird Survey data indicate a modest decline in overall numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159173017-MUK9UBF8LQ2N2ERY78Q7/SemipalmatedSandpiper.jpg Regional Birds - Semipalmated Sandpiper (Copy) Semipalmated Sandpiper - Status: Uncommon migrant. - Populations: These drab little sandpipers frequent mud flats on the plains in April-May and August-September. They nest on the Arctic Plain, from Alaska to Baffin Island. - Conservation: Construction of reservoirs on the plains of Boulder County has probably expanded migratory habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159189898-3PH1H83UMR4OENHI74W6/SemipalmatedPlover.jpg Regional Birds - Semipalmated Plover (Copy) Semipalmated Plover - Status: Uncommon spring migrant . - Populations: These striking sandpipers frequent mud flats of prairie ponds and reservoirs during April and May. They nest far to the north, in Alaska and northern Canada. - Conservation: Construction of reservoirs on the plains of Boulder County has probably expanded migratory habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159201178-AMPKPPJAGQDMYOWKDW5W/SpottedSandpiper.jpg Regional Birds - Spotted Sandpiper (Copy) Spotted Sandpiper - Status: Fairly common summer resident; uncommon migrant. - Populations: Spotted Sandpipers nest around prairie ponds and reservoirs, including Boulder Reservoir, Coot Lake, Sawhill Ponds, and Union Reservoir. Look for their "teetering" displays and listen for their clear, whistled flight calls. - Conservation: This widespread shorebird nests from the northern edge of the taiga in Alaska and Canada south to California and North Carolina. Colorado and North American populations appear secure--probably because they are able to nest in a wide variety of sites, including clumps of grass, among streamside rocks, under logs, and on ledges. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159209859-LJRKHI0B5QQ78OE50GHE/SolitarySandpiper.jpg Regional Birds - Solitary Sandpiper (Copy) Solitary Sandpiper - Status: Fairly common spring migrant; uncommon to rare fall migrant. - Populations: Look for these striking, medium-sized sandpipers during spring and late summer migration at Sawhill Ponds, Union Reservoir, Gayner Lakes, and Baseline Reservoir. They nest from Alaska east across central Canada to Newfoundland. - Conservation: North American Breeding Bird Survey data suggest a nonsignificant decline in numbers from 1966-2011. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159219049-3I0AZ0ITVROVA4QDDG3F/GreaterYellowlegs.jpg Regional Birds - Greater Yellowlegs (Copy) Greater Yellowlegs - Status: Fairly common spring and fall migrant. - Populations: Dozens migrate through Boulder County from March-April and July-October. Some may linger into December. They nest from Alaska east across Canada to Newfoundland. - Conservation: North American Breeding Bird Survey data indicate a nonsignificant increase in numbers from 1966-2011. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159230185-YJ4FYQ9ZHX0GHRPI3KEE/LesserYellowlegs.jpg Regional Birds - Lesser Yellowlegs (Copy) Lesser Yellowlegs - Status: Fairly common spring and fall migrant. - Populations: More abundant than Greater Yellowlegs, these long-legged shorebirds are hard to miss in April and May at Union Reservoir or Walden Ponds. They pass through Boulder County on their way south from August-October after nesting in Alaska and northern Canada. - Conservation: Populations remain fairly secure, since nesting habitat is in areas sparsely inhabited by humans. However, North American Breeding Bird Survey data indicate a nonsignificant decline in numbers from 1966-2011. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159241715-2RGKX0AWVX9I1LR6OPN5/MarbledGodwit.jpg Regional Birds - Marbled Godwit (Copy) Marbled Godwit - Status: Uncommon spring and fall migrant. - Populations: Fairly common on lakes and ponds in eastern Boulder County in April as they pass through on their way north to nesting areas in the prairie pothole region of the northern United States and south-central Canada. - Conservation: Breeding Bird Survey data indicate no significant increases or decreases since 1966, but historic breeding areas have been lost in Minnesota, Wisconsin, Iowa, and Nebraska since the early 20th century. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159252709-TH49VKRDU5A0FWH93JJC/BairdsSandpiper.jpg Regional Birds - Baird's Sandpiper (Copy) Baird's Sandpiper - Status: Uncommon to fairly common spring and fall migrant. - Populations: One of our most common sandpipers when flocks pass through in August and September, returning from nesting areas on the Arctic slope. Uncommon in May. - Conservation: Both breeding and wintering populations appear secure globally. Most of the moss tundra and low shrub tundra habitat where they nest remains intact. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159266296-IDTXDRMUBSTA74YUK7B2/WesternSandpiper.jpg Regional Birds - Western Sandpiper (Copy) Western Sandpiper - Status: Uncommon spring and fall migrant. - Populations: Look for them mixed in with flocks of other sandpipers at Boulder Reservoir, Walden Ponds, Baseline Reservoir, McIntosh Lake, and Union Reservoir in April-May and again in August-September. They nest in northern and western Alaska. - Conservation: Total population of about 3.5 million birds nests and winters in brackish tidal flats that receive minimal disturbance from humans. Drainage and conversion of wetlands at migration stopover points and wintering areas is probably the biggest threat to their populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159278618-A8DJ1ID94G1IX0C5S90E/WilsonsSnipe.jpg Regional Birds - Wilson's Snipe (Copy) Wilson's Snipe - Status: Fairly common to uncommon year-round resident. - Populations: Wilson's Snipes range all the way from the plains to the high mountains, where they nest in shallow marshes. Listen for the warbling, winnowing sound made by the wind rushing through the male's tail feathers as he display-dives over his nesting territory, April-June. - Conservation: This habitat generalist numbers more than 5 million in North America, but populations have contracted in areas hit by drought or where marshes have been converted to farmland or human settlements. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159289558-I996B9FB3G55TX7D5LHP/WilsonsPhalarope.jpg Regional Birds - Wilson's Phalarope (Copy) Wilson's Phalarope - Status: Fairly common migrant; uncommon summer resident. - Populations: Fairly common in shallow lakes and marshes on the plains in May and June, and a few pairs may nest successfully in Boulder County. We lie near the southern edge of their breeding range, which extends from northern New Mexico and Nevada northward to Yukon Territory, Saskatchewan, and Minnesota. - Conservation: Because of their dependence on shallow, ephemeral lakes and ponds, populations fluctuate wildly depending on the amount of rainfall. Nesting populations in the northern Great Plains have been hard hit by drought in recent years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159302880-O8G3AJZX6KJGNLID93E5/RedNeckedPhalarope.jpg Regional Birds - Red-necked Phalarope (Copy) Red-necked Phalarope - Status: Rare spring and fall migrant. - Populations: Red Phalaropes nest in tundra ponds along the Arctic Plain, and a few pass through Boulder County from year-to-year. This holarctic species nests from extreme northern Canada west through northern Russia and to Iceland. - Conservation: World population stands at around 5 million, though remoteness of nesting sites makes these shorebirds difficult to count. Northern Canada population show signs of declining. Likely vulnerable to oil spills and other disturbance of Arctic nesting habitat. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161188524-6KONE0IQUV3EB9JIZ62L/BonapartesGull.jpg Regional Birds - Bonaparte's Gull (Copy) Bonaparte's Gull - Status: Uncommon spring and fall migrant. - Populations: Look for these small, acrobatic gulls sprinkled in with flocks of Franklin's gulls on the plains in spring and migrating separately in October and November. They nest from southern Canada northward to Alaska. - Conservation: Breeding colonies lie in remote areas where there is minimal human disturbance, and little is known about population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161200400-M53469BJBUFXZ21HMMY8/FranklinsGull.jpg Regional Birds - Franklin's Gull (Copy) Franklin's Gull - Status: Fairly common spring, late summer, and fall migrant. - Populations: Flocks of several thousand pass through eastern Boulder County in late summer. Look for them especially at Union Reservoir and Boulder Reservoir, where they congregate on mud flats. They nest from northern Colorado north to Canada's Northwest Territories. - Conservation: The North American population stands at around one mullion, and little is known about population trends or conservation status, since most pairs breed in remote, large marshes that are difficult to census. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161209975-3Q1ZNFOZLNBU27WLEVRF/MewGull.jpg Regional Birds - Mew Gull (Copy) Mew Gull - Status: Rare winter resident. - Populations: This medium-sized, locally rare gull is difficult to distinguish from the locally common Ring-billed Gull. Note the smaller bill, shorter legs, and dark iris. Mew Gulls nest from north-central Canada west to the Aleutian Islands. - Conservation: Due to the remoteness of their nesting areas, little is known about population trends and conservation needs, but the total global population is estimated at more than one million nesting pairs. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161222222-95RXTBRV28FTZHGR9QPG/RingBilledGull.jpg Regional Birds - Ring-billed Gull (Copy) Ring-billed Gull - Status: Abundant winter resident and fairly common spring and fall migrant. Uncommon in summer. - Populations: Flocks of these medium-sized gulls gather on most lakes and ponds in Boulder County throughout the winter, and quite a few nonbreeding juveniles and adults stay for the summer months. Though ring-bills have nested in the San Luis Valley, their principal breeding range extends from Oregon, Wyoming, the Great Lakes, and Pennsylvania north to Northwest Territories and Labrador. - Conservation: World population stands at around 2.5 million, and dietary flexibility may protect this generalist from alterations to nesting and wintering habitat. Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161234367-AADRMQ733EQBTPSJEPJN/CaliforniaGull.jpg Regional Birds - California Gull (Copy) California Gull - Status: Fairly common spring and late summer migrant. Uncommon summer and winter resident. - Populations: California Gulls nest on sandy islands at Elevenmile Reservoir, in South Park; Riverside Reservoir east of Greeley; Adobe Creek Reservoir in North Park; and John Martin Reservoir in the Arkansas River valley. Their North American breeding range extends from California's Central Valley, the Great Salt Lake basin, and Colorado north to British Columbia and Northwest Territories. - Conservation: North American breeding populations appear to of the increased since the 1930s, and in Colorado, this colonial-nester has begun to breed on islands in large reservoirs. Since these aggressive gulls prey on nests of other ground-nesting birds, these new nesting colonies may threaten nesting populations of threatened least terns and piping plovers. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161285963-GFKHSJXCY648AWX6KU0E/HerringGull.jpg Regional Birds - Herring Gull (Copy) Herring Gull - Status: Fairly common winter resident and fall migrant. - Populations: Herring Gulls mix in with flocks of Ring-billed Gulls on Boulder County lakes from October-March. Note their larger size and distinctively pink legs. They nest from British Columbia, the Great Lakes area, and South Carolina north to Alaska and Labrador. - Conservation: U.S. breeding population has increased from around 8000 nesting pairs in 1900 to more than 100,000 nesting pairs in 1990. Larger numbers breed in Canada. Herring gulls thrive around human coastal communities, and humans have controlled nesting populations to protect other ground-nesting birds. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161297228-ZD3563Q2OYZ5NZ15AONE/ThayersGull.jpg Regional Birds - Thayer's Gull (Copy) Thayer's Gull - Status: Uncommon winter resident. - Populations: Distinguishable from Herring Gulls only by their darker iris and dark-streaked outer primary feathers, these large gulls gather with flocks of other gulls on Boulder County lakes and ponds throughout the winter. They nest in extreme northern Canada. - Conservation: Breeds in small, isolated colonies and is much less numerous than similar-appearing Herring Gull. Like other gulls, has benefited from construction of large landfills and reservoirs in wintering areas. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161311190-37G6WTJMNY3QCHEPXQY5/LesserBlackBackedGull.jpg Regional Birds - Lesser Black-backed Gull (Copy) Lesser Black-backed Gull - Status: Rare summer resident. - Populations: As you are scanning flocks of winter gulls with a scope or binoculars, look for individuals with darker wings. Lesser black-backs nest primarily in Europe. - Conservation: Persecuted populations were decimated during the 19th century and have slowly recovered since then, but this species remains threatened throughout much of its European breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161322772-CFCYAGUUA28JTQFUHNTY/BlackTern.jpg Regional Birds - Black Tern (Copy) Black Tern - Status: Uncommon spring and late summer migrant. Nests just east and north of Boulder County. - Populations: These acrobatic terns swoop over prairie reservoirs in late spring and late summer, and a few pairs nest in Eastern Colorado. Nesting pairs are fairly common in the Nebraska Sandhills and northward into the prairie pothole region of the Dakotas and southern Canada. - Conservation: North American Breeding Bird Survey data indicated an average annual decline of 3.1% from 1966-96, with the greatest decline occurring within the prairie region. Loss or degradation of wetlands where black terns nest or overwinter remains a major concern. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161332932-G9SJ97G9G80FHA8732CF/ForstersTern.jpg Regional Birds - Forster's Tern (Copy) Forster's Tern - Status: Uncommon spring and late summer migrant. Nests just east and north of Boulder County. - Populations: These acrobatic terns swoop over prairie reservoirs in late spring and late summer, and a few pairs nest in Eastern Colorado. Nesting pairs are fairly common in the Nebraska Sandhills and northward into the prairie pothole region of the Dakotas and southern Canada. - Conservation: North American Breeding Bird Survey data indicated an average annual decline of 3.1% from 1966-96, with the greatest decline occurring within the prairie region. Loss or degradation of wetlands where black terns nest or overwinter remains a major concern. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162135394-BAO4MO7PPVL05VY6JL3L/RockDove.jpg Regional Birds - Rock Pigeon (Dove) (Copy) Rock Pigeon (Dove) - Status: Abundant year-round resident. - Populations: Rock Doves, commonly known as Pigeons, which were introduced to North America from Europe, nest on cliffs, buildings, and other structures throughout Boulder County from the plains to mountain communities. - Conservation: Efforts to poison pigeons in parts of North America have not led to dramatic declines in their numbers. They continue to thrive wherever humans are present. Photo © 2013, Alan Grant https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162145170-I5V6S4ZKLK7873ZV0YMN/MourningDove.jpg Regional Birds - Mourning Dove (Copy) Mourning Dove - Status: Common summer resident; uncommon winter resident. - Populations: These urban-adapted, habitat generalists nest in shrubby environments throughout the plains, foothills, and low mountains of Boulder County. - Conservation: One of the most abundant birds in North America with an estimated population of 300-500 million individuals. Populations appear to have declined in areas invaded by Eurasian Collared-Doves and in agricultural areas where shrubbery and woodlots have been removed. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162155815-YNQJTZFPWSVT8JBGQ2VY/EurasianCollaredDove.jpg Regional Birds - Eurasian Collared Dove (Copy) Eurasian Collared Dove - Status: Fairly common year-round resident. - Populations: Eurasian collared-doves first appeared in Boulder County around 2000 and now thrive on the plains and in the low foothills. Native to the Indian subcontinent, they were distributed around the world through the caged bird trade and now inhabit most of North America, from Florida to Alaska. - Conservation: Populations have exploded across North America during the past two decades. It's still not known how much they compete with or displace native mourning doves. Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162809161-Z96BKJENYUR14OD3FJ52/BarnOwl.jpg Regional Birds - Barn Owl (Copy) Barn Owl - Status: Uncommon summer resident; rare winter resident. - Populations: Barn owls were first documented nesting in Boulder County in 1943, when a cliff nest was found at White Rocks, along Boulder Creek. They now nest in tree cavities, cliffs, barns, silos, and other human structures throughout the plains. - Conservation: While populations have declined in areas of the Great Plains as dead trees and old barns have been removed and rodent populations reduced by use of pesticides, numbers have increased steadily in Boulder County during the last several decades. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162820379-ITLMTC3VA2K6R0Y75C1B/FlammulatedOwl.jpg Regional Birds - Flammulated Owl (Copy) Flammulated Owl - Status: Uncommon summer resident. - Populations: These tiny, reclusive owls nest in woodpecker holes in aspen groves or mature ponderosa pine woodlands from 6000-10,000 feet. Listen for their surprisingly forceful hooting calls as they advertise nesting territories in late spring. - Conservation: Little is known about Flammulated Owl population trends in North America. In Boulder County they appear to thrive in old-growth ponderosa pine woodlands and mature aspen groves, both of which have been reduced by subdivision development, catastrophic fires, and insect infestations. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162828623-LPG3XTD8SU3F48OP38SY/EasternScreechOwl.jpg Regional Birds - Eastern Screech Owl (Copy) Eastern Screech Owl - Status: Uncommon year-round resident. - Populations: Boulder County Nature Association studies suggest that about one pair per linear mile nests along St. Vrain Creek and Boulder Creek on the plains. Pairs also nest in city parks in Boulder, Louisville, Longmont, and other communities--wherever there are tree cavities and sufficient prey populations. - Conservation: Little is known about eastern screech-owl population trends in Colorado. Populations appear to be stable or slightly increasing in Boulder County as density of deciduous woodlands on the plains and in towns increases. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162837487-U2Y06CN1ADNG7ED283GB/GreatHornedOwl.jpg Regional Birds - Great Horned Owl (Copy) Great Horned Owl - Status: Fairly common year-round resident. - Populations: These human-adapted habitat generalists nest throughout Boulder County, from towns on the plains to subalpine forests. They usually use abandoned hawk nests, but may also lay their eggs in tree cavities and broken-topped snags. - Conservation: Great horned owl populations have exploded in Boulder County, threatening nesting populations of prey species that include long-eared owl and burrowing owl. The number observed on Boulder Christmas Bird Counts increased from 1 in 1950 to more than 100 in 2013. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162848580-ZMA24V9K32BOJ1X3YU8Y/NorthernPygmyOwl.jpg Regional Birds - Northern Pygmy Owl (Copy) Northern Pygmy Owl - Status: Fairly common year-round resident. - Populations: These human-adapted habitat generalists nest throughout Boulder County, from towns on the plains to subalpine forests. They usually use abandoned hawk nests, but may also lay their eggs in tree cavities and broken-topped snags. - Conservation: Great horned owl populations have exploded in Boulder County, threatening nesting populations of prey species that include long-eared owl and burrowing owl. The number observed on Boulder Christmas Bird Counts increased from 1 in 1950 to more than 100 in 2013. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592163597618-UPWLOOY3F5J8JU195UYW/BurrowingOwl.jpg Regional Birds - Burrowing Owl (Copy) Burrowing Owl - Status: Uncommon summer resident. - Populations: Pairs arrive in prairie dog colonies on the plains in April, laying their eggs in abandoned prairie dog burrows by mid-May. They often line nest burrows with dung, which they apparently used to attract beetles and other insect prey. Nests can fledge anywhere from 1 to 10 young. - Conservation: Once considered abundant in Boulder County, burrowing owls now nest in only a few scattered locations, and nest productivity appears to be too low to maintain stable populations. Fragmentation of prairie dog colony nesting habitat, along with mortality from automobile collisions and predation by urban-adapted predators, appear to be the greatest threats to their survival locally. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162872388-VFXWPITYBIZ58TUOBTH1/LongEaredOwl.jpg Regional Birds - Long-eared Owl (Copy) Long-eared Owl - Status: Uncommon to rare year-round resident. - Populations: Considered fairly common in Boulder County plains and foothills woodlands during the late 19th century, long-eared owls are now difficult to find, with only a half dozen nesting locations documented during the past two decades. Predation by larger and more suburban-adapted great horned owls may pose the greatest threat to their survival. - Conservation: Imperiled in Boulder County, possibly due to competition with and predation by larger great horned owls. Listed as threatened or endangered in a half dozen states. However, due to their secrecy and nomadism, little is known about long-term North American population trends. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162880893-9H7IRWPXTBAC8VROFIPF/ShortEaredOwl.jpg Regional Birds - Short-eared Owl (Copy) Short-eared Owl - Status: Rare winter resident. - Populations: One or two short-eared owls tend to appear in wetlands west of Boulder Reservoir and west of Lagerman Reservoir each winter. Look for them swooping low over cattail marshes around dusk or dawn. There is just one nesting record for Boulder County, from the late 19th century. - Conservation: Despite widespread concern over their decline in specific areas, listed as "secure" by the Nature Conservancy. Has always been considered rare in Boulder County, though numbers of observations appear to have declined during recent years. Loss of wetlands surrounded by natural grasslands is a primary concern. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162891046-7HJPZRARWM0K305UJM26/NorthernSawWhetOwl.jpg Regional Birds - Northern Saw-whet Owl (Copy) Northern Saw-whet Owl - Status: Rare winter resident. - Populations: One or two short-eared owls tend to appear in wetlands west of Boulder Reservoir and west of Lagerman Reservoir each winter. Look for them swooping low over cattail marshes around dusk or dawn. There is just one nesting record for Boulder County, from the late 19th century. - Conservation: Despite widespread concern over their decline in specific areas, listed as "secure" by the Nature Conservancy. Has always been considered rare in Boulder County, though numbers of observations appear to have declined during recent years. Loss of wetlands surrounded by natural grasslands is a primary concern. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162901216-20E1PPP4OQ8JVEH8C9TK/BorealOwl.jpg Regional Birds - Boreal Owl (Copy) Boreal Owl - Status: Uncommon year-round resident. - Populations: Boreal owls nest almost exclusively in the boreal, or subalpine life zone. They were first detected in Boulder County in 1984, when their haunting, winnowing calls were heard near Brainard Lake and west of Eldora. Breeding studies indicate there is little or no overlap between their nesting habitat and that of the closely related northern saw-whet owl. - Conservation: Due to the difficulty of surveying breeding habitat in the high mountains during the late winter and spring calling and nesting period, little is known about boreal owl populations in Boulder County and throughout Colorado. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180196478-93KXZ942KGDYBM97RIUL/CommonNighthawk.jpg Regional Birds - Common Nighthawk (Copy) Common Nighthawk - Status: Fairly common summer resident. - Populations: Nests on the ground from the plains to the upper montane, predominantly in shortgrass prairie and ponderosa pine woodlands. Listen for the fart-like "vroorror" as males dive over their nesting territories and the wind rushes through their feathers. - Conservation: Fragmentation of native grasslands by crops and towns, along with suburbanization of areas at the base of the Front Range foothills, have contributed to apparent declines in Colorado nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180206988-5A65KS4WH6TUWJJO7QD6/CommonPoorwill.jpg Regional Birds - Common Poorwill (Copy) Common Poorwill - Status: Fairly common summer resident. - Populations: Nests on the ground from the plains to the upper montane, predominantly in shortgrass prairie and ponderosa pine woodlands. Listen for the fart-like "vroorror" as males dive over their nesting territories and the wind rushes through their feathers. - Conservation: Fragmentation of native grasslands by crops and towns, along with suburbanization of areas at the base of the Front Range foothills, have contributed to apparent declines in Colorado nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180216354-I5WKO16FPMWUUN9LV3NC/ChimneySwift.jpg Regional Birds - Chimney Swift (Copy) Chimney Swift - Status: Uncommon summer resident. - Populations: First discovered nesting in Boulder County in chimneys of the University of Colorado's Mackey Auditorium, these urban-adapted swifts have slowly spread up and down the Front Range. However, they are rarely seen except when entering or leaving nesting chimneys. - Conservation: Not surprisingly, these urban-adapted swifts appear to have expanded throughout Eastern Colorado as human settlements have proliferated. However, Breeding Bird Survey data suggest that North American populations are declining. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180227787-JLPMBMDYDSZI35TL4IX8/WhitethroatedSwift.jpg Regional Birds - White-throated Swift (Copy) White-throated Swift - Status: Uncommon summer resident. - Populations: First discovered nesting in Boulder County in chimneys of the University of Colorado's Mackey Auditorium, these urban-adapted swifts have slowly spread up and down the Front Range. However, they are rarely seen except when entering or leaving nesting chimneys. - Conservation: Not surprisingly, these urban-adapted swifts appear to have expanded throughout Eastern Colorado as human settlements have proliferated. However, Breeding Bird Survey data suggest that North American populations are declining. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180254518-CBU5XGKKJDO6XRWTITMJ/BroadTailedHummingbird.jpg Regional Birds - Broad-tailed Hummingbird (Copy) Broad-tailed Hummingbird - Status: Common summer resident. - Populations: Nesting from the low foothills to the high mountains, broad-tails are conspicuous because of the distinctive trilling sound that the male makes with his wings while patrolling nesting territories. They like wet areas, especially aspen groves and streamside woodlands. - Conservation: Their adaptability to hummingbird feeders and to humans in general has no doubt enabled broad-tails to expand their nesting populations in some areas. They breed all the way from northern Wyoming south to Guatemala. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180466882-X0HSK614YHNBM8HOLMD0/RufousHummingbird.jpg Regional Birds - Rufous Hummingbird (Copy) Rufous Hummingbird - Status: Fairly common summer migrant. - Populations: These beautiful and feisty hummingbirds nest from northern California and northwestern Wyoming all the way up to Alaska and Yukon Territory. In spring they migrate north through California's Central Valley, where nectar-laden wildflowers are already blooming; in late summer they migrate south through wildflower meadows of the Central Rockies. - Conservation: Breeding Bird Survey data show significant declines in British Columbia, Washington, and Oregon. Forestry activities may affect nesting success, but the estimated world population nevertheless stands at a fairly robust 6.5 million. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180482549-TZ3VGGMKJVCYUKDP3C09/BeltedKingfisher.jpg Regional Birds - Belted Kingfisher (Copy) Belted Kingfisher - Status: STATUS - Populations: Belted Kingfishers nest throughout much of North America, laying their eggs in burrows in a steep earthen bank0, usually close to water. They eat mainly small fish. Listen for their chattering calls as they zoom over streams and gravel ponds on the plains. - Conservation: North American populations appeared to decline by approximately 50% from 1974-94. However, populations appear stable or are increasing in Boulder County. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181367585-R61XTL5T2WUJ5A6LIWHV/WilliamsonsSapsuckerMale.jpg Regional Birds - Williamson's Sapsucker (male) (Copy) Williamson's Sapsucker (male) - Status: Fairly common resident of mountain conifer forests. - Populations: Listen for the Morse code-like rapping of these gregarious woodpeckers in mid- to high-elevation forests. Males excavate nest cavities in aspens or sometimes conifers. - Conservation: Breeding from southeastern British Columbia to central Arizona and New Mexico, these sapsuckers thrive in ponderosa pine forest and aspen groves. Their numbers increase during outbreaks of insect infestations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181377762-RETWJWPPVPV79ZN0T4PJ/WilliamsonsSapsuckerFemale.jpg Regional Birds - Williamson's Sapsucker (female) (Copy) Williamson's Sapsucker (female) - Status: Fairly common resident of mountain conifer forests. - Populations: Listen for the Morse code-like rapping of these gregarious woodpeckers in mid- to high-elevation forests. Males excavate nest cavities in aspens or sometimes conifers. - Conservation: Breeding from southeastern British Columbia to central Arizona and New Mexico, these sapsuckers thrive in ponderosa pine forest and aspen groves. Their numbers increase during outbreaks of insect infestations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181752960-AGRBZZ4AKGKG82T4XMKX/RedNapedSapsucker.jpg Regional Birds - Red-naped Sapsucker (Copy) Red-naped Sapsucker - Status: Fairly common resident in mountain aspen groves. - Populations: These small sapsuckers typically forage in deciduous woodlands and excavate their nest cavities in dead or dying aspens. The noisy chatter of young sapsuckers makes these nests relatively easy to find. In Boulder County they range from about 6000-10,500 feet. - Conservation: Forestry practices that eliminate dead or dying trees may limit nesting populations, but these sapsuckers still appear to be thriving throughout the mountains of Colorado. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181403394-4EX7NFLK8QINH0NJIK50/DownyWoodpecker.jpg Regional Birds - Downy Woodpecker (Copy) Downy Woodpecker - Status: Fairly common resident in mountain aspen groves. - Populations: These small sapsuckers typically forage in deciduous woodlands and excavate their nest cavities in dead or dying aspens. The noisy chatter of young sapsuckers makes these nests relatively easy to find. In Boulder County they range from about 6000-10,500 feet. - Conservation: Forestry practices that eliminate dead or dying trees may limit nesting populations, but these sapsuckers still appear to be thriving throughout the mountains of Colorado. Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181430932-EEYKY05GTO3GDKGHNUN5/HairyWoodpecker.jpg Regional Birds - Hairy Woodpecker (Copy) Hairy Woodpecker - Status: Common year-round resident, primarily foothills and mountains. - Populations: Hairy Woodpeckers excavate nest cavities primarily in conifers from plains communities to high-elevation mountain forests. Their "peeek" calls are slightly lower pitched and their bills longer than those of the smaller downy woodpeckers. - Conservation: These generalists have continued to thrive throughout central and western Colorado despite forestry activities that limit the availability of potential nesting trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181441945-M3WB8K90SGFCO7SVEBZH/ThreeToedWoodpecker.jpg Regional Birds - Three-toed Woodpecker (Copy) Three-toed Woodpecker - Status: Uncommon year-resident of mountain forests, most abundant in recently-burned areas. - Populations: In years following a fire, these small woodpeckers forage on wood-borers that chew on the fire-killed trees. They excavate their nest cavities in dead or dying conifers from 7000-12,000 feet. - Conservation: These mountain-dwelling woodpeckers nest in boreal forests from Scandinavia, Northern Europe, and Asia to North America, primarily in areas with widely-dispersed human populations. However, fire-suppression in conifer forests has probably reduced foraging and nesting opportunities. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181451571-PXG5TD8KPQ1FN2PHJUVO/NorthernFlicker.jpg Regional Birds - Northern Flicker (Copy) Northern Flicker - Status: Very common year-around resident throughout Boulder County. - Populations: These urban-adapted generalists excavate nest cavities in cottonwoods, aspens, conifers, fence posts, utility poles, or the siding of human dwellings from the plains to the high mountains. They feast on grasshoppers, crickets, caterpillars, and various other insect larvae. - Conservation: Northern Flickers appear to be thriving throughout Boulder County and throughout most of North America. Competition with European Starlings may limit populations in some areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186880326-FO1ZDZD43P6WCBRJYNQV/OliveSidedFlycatcher.jpg Regional Birds - Olive-sided Flycatcher (Copy) Olive-sided Flycatcher - Status: Uncommon summer resident in foothills and lower mountain forests. - Populations: These medium-sized flycatchers, famous for their distinctive "whip-three-beers" song, inhabit ponderosa pine and other open forests from Walker Ranch westward to the low subalpine zone. They also breed in open aspen forests, hiding their nests high in trees among clusters among clusters of horizontal branches. - Conservation: Populations have declined sharply throughout North America in recent decades. Changes in winter habitats and densification of conifer forests in North America may have contributed to this decline. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186891653-JYS4HYPY94S59HDDX5JR/WesternWoodPewee.jpg Regional Birds - Western Wood-Pewee (Copy) Western Wood-Pewee - Status: Common summer resident in deciduous and conifer forests from the plains to middle elevations. - Populations: These perky flycatchers nest primarily in riparian woodlands on the plains and ponderosa pine woodlands in the foothills. They place their cup nests 8-80 feet above the ground on a horizontal limb. Most easily recognized by their song, there also are our only common small flycatcher with no distinct eye-ring. - Conservation: These cosmopolitan flycatchers breed throughout western North America, from eastern Alaska to eastern North Dakota, then south to Mexico and Central America. Breeding Bird Survey data suggest a significant decline in continental populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186903716-DD3MJ40CMXW9PDMJ3BML/HammondsFlycatcher.jpg Regional Birds - Hammond's Flycatcher (Copy) Hammond's Flycatcher - Status: Fairly common summer resident in conifer forests from the foothills to the high mountains. - Populations: These small flycatchers breed in open conifer forests from 6000-10,000 feet, concealing their nests among conifer needles on horizontal branches. They are virtually identical in appearance and voice to Dusky Flycatchers (though the Dusky's song is somewhat lighter and can be higher-pitched), but Duskys nest mostly in deciduous woodlands. - Conservation: Because of their preference for open and mature conifer forests, populations may be declining in areas where forests have become unnaturally dense. Periodic burning of conifer forests should benefit this flycatcher. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186918828-7I2YAU1I3QZW96SXO7KJ/DuskyFlycatcher.jpg Regional Birds - Dusky Flycatcher (Copy) Dusky Flycatcher - Status: Fairly common summer resident in deciduous woodlands, including aspen groves, from the foothills to around 11,000 feet. - Populations: Dusky flycatchers nest in a variety of mostly deciduous habitats, including willows, aspen groves, and open conifer forests. Females build soft, neatly woven nests from grasses and finely shredded plant material and place them in the crotches of shrubs or branches, usually within 15 feet of the ground. - Conservation: These adaptable flycatchers breed from southwestern Yukon, Alberta, and Saskatchewan south throughout most of the mountains of North America. Populations appear to be steady or increasing throughout much of western North America. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186932636-WMKHX8PH7ZJS6ZEIQRHJ/CordilleranFlycatcher.jpg Regional Birds - Cordilleran Flycatcher (Copy) Cordilleran Flycatcher - Status: Fairly common summer resident in aspen groves, willow thickets, and ponderosa pine forests. - Populations: Easily recognized by their high-pitched, rising "bir-dee" song, these active flycatchers place their nests on rock faces, cut banks, barn eaves, and banks of streams in open areas of the forest. - Conservation: Construction of mountain cabins and barns probably has benefited nesting populations in Boulder County. No clear population trends have been identified throughout their breeding habitat, which extends throughout the mountains of North America from southern Alberta south to Oaxaca. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186943054-NN3UYVZQORWHGOZUVSAL/SaysPhoebe.jpg Regional Birds - Say's Phoebe (Copy) Say's Phoebe - Status: Fairly common summer resident, primarily on the plains. - Populations: These suburban-adapted flycatchers nest under building eaves, cliff crevices, and in recycled cliff swallow nests from the plains to about 9000 feet. They forage for insects from low perches on rocks, bushes, fence posts, and small trees. - Conservation: Widely distributed throughout low- to middle elevations of Colorado and the Mountain West, Say's Phoebes appear to be holding their own, though urbanization threatens nesting populations in some areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186956876-A4TQS2W41TFY2NCTRQD4/WesternKingbird.jpg Regional Birds - Western Kingbird (Copy) Western Kingbird - Status: Fairly common summer resident on the plains. - Populations: Breeding pairs arrive in Colorado and April and begin building their cup nests in cottonwoods and other deciduous trees in May. They may also place their nests on building ledges, telephone poles, fence posts, windmills, stumps, or in tree cavities. - Conservation: Western Kingbirds breed throughout much of western North America, and their populations appear to be stable or increasing. Planting and maturing of deciduous trees along the rivers and around farmhouses on the plains has probably benefited nesting populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186971954-46UJPJM8G89DV7VRPGQE/EasternKingbird.jpg Regional Birds - Eastern Kingbird (Copy) Eastern Kingbird - Status: Fairly common summer resident on the plains. - Populations: Though their breeding range overlaps with that of the Western Kingbird, Eastern kingbirds tend to associate more closely with woodlands adjacent to open water. Look for them in woodlands along Boulder Creek and St. Vrain Creek and in cottonwood groves surrounding reservoirs on the plains. - Conservation: Eastern Kingbirds winter in South America and nest from Nevada and British Columbia to the eastern seaboard. Rural development in Colorado, often accompanied by the planting of trees, has provided new breeding opportunities for this wide-ranging kingbird. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186983472-C46KLJ3BLV6DL01R3TTP/LoggerheadShrike.jpg Regional Birds - Loggerhead Shrike (Copy) Loggerhead Shrike - Status: Uncommon to rare summer resident of the plains. - Populations: These predatory songbirds nest in open habitats where they capture and impale insects and small mammals on thorns and barbed-wire. They typically place their nests in scattered trees surrounded by grasslands or shrublands. - Conservation: While nesting strikes may have benefited from the planting of trees and construction of barbed-wire fences on the eastern plains, nesting populations have plummeted in Boulder County. Destruction and fragmentation of shortgrass prairies has probably fueled this local decline. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186992340-WL7P40EP0SMRJCXRTIKR/NorthernShrike.jpg Regional Birds - Northern Shrike (Copy) Northern Shrike - Status: Uncommon winter resident on the plains. - Populations: Northern Shrikes nest in the boreal forests of northern Canada, from Alaska east to Labrador. Individuals winter as far south as Arizona, feeding on insects and small mammals. They prefer open country, where they sometimes perch high in snags or sparsely-vegetative trees. - Conservation: No clear trends have been documented in Boulder County numbers since the late nineteenth century. Awesome Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592187001447-EHYZTOVE7H81R9LFE3QP/PlumbeousVireo.jpg Regional Birds - Plumbeous Vireo (Copy) Plumbeous Vireo - Status: Fairly common summer resident in open conifer forests in the foothills and low mountains. - Populations: These laid-back, slow-moving vireos are among the easiest songbirds to find in our ponderosa pine woodlands, as they sing from prominent perches and often place their nests near to the ground on dead branches. Their slow, rhythmical song fills our foothills forests throughout the summer. - Conservation: Plumbeous Vireos nest throughout the Rocky Mountains and Great Basin of the western United States and winter in western Mexico. Suppression of natural disturbance (especially fire) in Colorado ponderosa pine forests may create crowded forests unsuitable for nesting. Loss of wintering habitat in Mexico is another potential threat. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592187011416-95V0BZUN3MFICQ2SLDCO/WarblingVireo.jpg Regional Birds - Warbling Vireo (Copy) Warbling Vireo - Status: Common summer resident in deciduous woodlands from the plains to around 10,000 feet. - Populations: In Boulder County these sweet-singing vireos nest primarily in cottonwoods on the plains and aspen groves in the foothills. Males sing while on the nest, often located within 12 feet of the ground. - Conservation: Breeding Bird Survey trends show Warbling Vireo populations increasing throughout much of their nesting range, which includes most of the United States and southern Canada. However, loss of aspen groves and pesticide contamination of insect prey pose potential threats to nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771380378-P8LVRR5AX9MO5S6X8VZX/GrayJay.jpg Regional Birds - Gray Jay (Copy) Gray Jay - Status: Fairly common year-round resident of high mountain conifer forests. - Populations: These garrulous mountain jays nest in conifer forests from about 8500' to treeline. They mix scavenged food with saliva, roll it into a ball, and store this bolus on a limb under bark or lichens. They are attracted to humans and will snatch sandwich bits out of your hand if you're not watching carefully. - Conservation: Numbers appear to be stable in Colorado, and no changes in their overall statewide range have been noted since 1900. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771397816-DAWXHK3XHKTLC638D4XX/StellersJay.jpg Regional Birds - Steller's Jay (Copy) Steller's Jay - Status: Very common year-round resident, primarily in foothills and mountain conifer forests. - Populations: These audacious jays inhabit conifer forests throughout Colorado, where they feed on insects, scavenge food scraps, and occasionally rob other birds' nests of eggs and young. They are readily attracted to humans and our picnic leavings and often follow hikers and skiers through the woods. - Conservation: Steller's Jays appear to be thriving throughout their historical Colorado range as they adapt to humans and our bird feeders and table scraps. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771410578-9UV0S4JMEUFEG3RH109D/BlueJay.jpg Regional Birds - Blue Jay (Copy) Blue Jay - Status: Common year-round resident in urban areas and riparian woodlands on the plains. - Populations: Originally inhabitants of mixed deciduous forests, these adaptable jays have followed deciduous trees westward and learned to live among humans in urban areas. More than 75% of their food comes from vegetable matter, including nuts, acorns, seeds, berries, and other fruit. They typically nest in deciduous trees or shrubs. - Conservation: Blue Jays were first reported in Colorado in 1903 and first reported nesting in 1905 near Yuma. They eventually reached virtually all the northern Front Range cities and have begun to move up into the mountains, where they sometimes hybridize with native Steller's Jay's. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771422605-A5ZK95G7Z0RNEFPV24UX/WoodhousesScrubJay.jpg Regional Birds - Woodhouse's Scrub Jay (Copy) Woodhouse's Scrub Jay - Status: Fairly common year-round resident in shrub communities, primarily at the base of the foothills. - Populations: Historically, Woodhouse’s Scrub-jays were reported primarily in scrub-oak woodlands, primarily on the Western Slope. Recently they have spread into shrublands throughout the Front Range foothills and much of southeastern Colorado. They nest in shrub thickets where they feed on acorns, piñon nuts, and other fruits and seeds. However, during the nesting season they may feed primarily on insects. - Conservation: Numbers appear to be stable throughout most of their Colorado nesting range, although populations continue to expand east of the mountains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771431977-6U79ZWH7OMPL956FWAT9/ClarksNutcracker.jpg Regional Birds - Clark's Nutcracker (Copy) Clark's Nutcracker - Status: Fairly common year-round resident of high mountain conifer forests. - Populations: These large, resourceful jays nest primarily in spruce-fir and other mixed conifer forests above 8000 feet, where they feed on seeds, berries, insects, small mammals, and carrion. A single individual can carry 70 are more seeds in its sublingual pouch and may cache up to 10,000 seeds (primarily in the ground) during a single season. - Conservation: Because nutcrackers are so wide-ranging and their nests not particularly easy to find, little is known about population trends in Colorado. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771440587-VKQQV2TOXXP7BO78AU24/BlackBilledMagpie.jpg Regional Birds - Black-billed Magpie (Copy) Black-billed Magpie - Status: Very common year-round resident of shrublands, riparian woodlands, and open conifer forests from the plains to the high mountains. - Populations: Black-billed magpies nest in shrublands, open conifer forests, woodlands, and urban edges throughout Colorado. They build mud and stick nests surrounded by globular stick structures, and they feed on pretty much anything they can find, including insects, wild fruits, and carrion. They often perch on the backs of deer, elk, and livestock, where they feed on ticks. - Conservation: Paradoxically, Breeding Bird Survey data show this cosmopolitan species decreasing in North America, including on the High Plains. Magpies' intolerance of high summer heat levels may partially explain this observed decline. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771450500-CSZARX9OMG5MS8S3CWWZ/AmericanCrow.jpg Regional Birds - American Crow (Copy) American Crow - Status: Very common year-round resident from the plains to the high mountains; thrives in urban areas. - Populations: American Crows nest from the plains to up to 10,000 feet, traveling in enormous flocks in winter but usually separating out into breeding pairs in spring and summer. They build their nests in trees, shrubs, or on utility poles and scavenge fruits, insects, and carrion. - Conservation: Crows thrive wherever humans live, and Breeding Bird Survey data show a gradual population increase nationally. In Colorado crows have expanded their range into urban and suburban areas, especially in the southern half of the state. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771462014-2SA95C2EYMKAT2P4GNDI/CommonRaven.jpg Regional Birds - Common Raven (Copy) Common Raven - Status: Very common year-round resident, plains and foothills. Nests primarily on cliffs and thrives around urban areas. - Populations: Common Ravens breed primarily in mountain forests, though in recent years more pairs have nested in suburban areas on the plains. They eat carrion, small rodents, insects, wild fruits, and grains. They nest primarily on cliffs but also in trees and on power poles. - Conservation: Considered rare in eastern Colorado during the late 19th century, ravens have spread up and down the Front Range, taking advantage of road-kills and other food provided by humans. Believe it or not, Chihuahuan Ravens were more abundant than Common Ravens in Boulder County during the first half of the 20th century. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772428540-ELN0OZGRMIIS2OXMKB1A/HornedLark.jpg Regional Birds - Horned Lark (Copy) Horned Lark - Status: Fairly common year-round resident on the plains; common summer resident in the Alpine tundra. - Populations: Possibly the most abundant breeding bird in Colorado, Horned Larks nest in close-cropped shortgrass prairies on the plains and in similar environments in the Alpine tundra. They breed across Europe, Asia, northern Africa, and in North America from the Alaskan tundra south to the Andes. - Conservation: Horned Larks remain the most abundant species on many Colorado Breeding Bird Survey routes, though survey data do indicate a moderate decline across North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772439934-DV8NY13C3XNLA5PFZXKA/TreeSwallow.jpg Regional Birds - Tree Swallow (Copy) Tree Swallow - Status: Common summer resident from the plains to the high mountains. - Populations: These acrobatic swallows typically nest in tree cavities in open forests near water. Locally, they nest from the plains to the high mountains, with nests especially abundant in aspen groves. They carefully line their cavity-nests with feathers, and studies indicate that young birds thrive in well-feathered nests. - Conservation: Tree Swallows nest across North America from northern Canada south to Georgia, Arkansas, and south-central California. North American populations appear to have increased in recent years, and their breeding range has expanded into the southeastern United States and formerly treeless areas on the Great Plains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772450507-CG9SNR8TBSG44NF5750Z/VioletGreenSwallow.jpg Regional Birds - Violet-green Swallow (Copy) Violet-green Swallow - Status: Common summer resident from the plains to the high mountains. - Populations: Nesting in similar sites to those occupied by Tree Swallows, Violet-green Swallows appear to be more abundant in the foothills and in cliffy areas, where they nest in cliff crevices. However, nesting pairs are most abundant in aspen groves. - Conservation: Considered the second most common breeding swallow in Colorado after Cliff Swallow, Violet-green Swallows breed in western North America, from Alaska to Mexico. Cutting of dead trees and invasion of urban area nesting sites by house sparrows and European starlings may restrict populations in some areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772463087-94UD9ZC4UTT9PTSIZNDJ/NorthernRoughWingedSwallow.jpg Regional Birds - Northern Rough-winged Swallow (Copy) Northern Rough-winged Swallow - Status: Fairly common summer resident on the plains and in the foothills. - Populations: These drab but swift-flying swallows typically nest in dirt embankments near streams or gravel ponds. Pairs tend to nest separately, rather than in colonies. - Conservation: Northern Rough-winged Swallows breed throughout the United States and southern Canada south through Central America. They typically arrive in Colorado in March or April. Their breeding range has expanded in the eastern United States in recent years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772477892-K8QI6VHL0EFT0NOCUMRZ/BankSwallow.jpg Regional Birds - Bank Swallow (Copy) Bank Swallow - Status: Uncommon summer resident on the plains. - Populations: These colonial, bank-nesting swallows breed in just a few locations in Boulder County, including a gravel pile at Walden Ponds Wildlife Area. They dig their own burrows, then build a nest of dry vegetation and feathers at the end of the burrow. - Conservation: These swallows breed nearly worldwide, but only scattered populations nest in Colorado, mostly on the plains and in the western valleys. While they may benefit from sand and gravel operations, the shifting nature of these operations and destruction of natural embankments may limit their nesting success. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772488507-J8SXOTOQRDT5NA4PT4EY/CliffSwallow.jpg Regional Birds - Cliff Swallow (Copy) Cliff Swallow - Status: Very common summer resident, plains to middle elevations. - Populations: Our most abundant swallows, Cliff Swallows nest by the hundreds in colonies under bridges, in culverts, and under overhanging cliffs, primarily on the plains and in the foothills. Their beautifully constructed gourd-shaped mud nests make colonies easy to find, even during winter. - Conservation: Breeding Bird Survey trends indicate a continent-wide increase in nesting populations during recent decades. These suburban-adapted swallows may benefit from construction of bridges and culverts, though humans frequently destroy their nests when they're located on buildings. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772499734-U3NT49GMYRPGQFKUU2AB/BarnSwallow.jpg Regional Birds - Barn Swallow (Copy) Barn Swallow - Status: Very common summer resident on the plains and in mountain communities. - Populations: Aptly-named barn swallows frequently nest inside or under the eaves of barns and other outbuildings, though before European conquest, they nested primarily in caves and on cliffs. Less colonial than Cliff Swallows, they spread out across the landscape, nesting in virtually all human-occupied areas of Colorado. - Conservation: Considered the most widespread of all swallows, Barn Swallows nest in North America, Europe, Africa, and Asia. Colorado breeders winter from Panama south to Argentina and Chile. North American populations appear to be increasing as these urban-adaptive swallows take advantage of human structures and proliferation of deciduous trees in and around human settlements. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775286145-W5SIV5AALOE1AJ92O71H/BlackCappedChickadee.jpg Regional Birds - Black-capped Chickadee (Copy) Black-capped Chickadee - Status: Common year-round resident on the plains and in mountain aspen groves. - Populations: We tend to associate these perky chickadees with riparian woodlands on the plains, but surprisingly most nesting pairs are found in aspen groves and riparian woodlands in the mountains. They excavate their own cavity-nests in soft bark and line them with fiber, moss, cocoons, feathers, wool, and hair. - Conservation: Suppression of natural fires has reduced nesting opportunities in ponderosa pine woodlands in the foothills. Across North America, breeding populations appear to be increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775299093-JAYQVW0WLB4U53RE9WX7/MountainChickadee.jpg Regional Birds - Mountain Chickadee (Copy) Mountain Chickadee - Status: Common year-round resident in conifer forests. - Populations: Much more abundant in Colorado than black-caps, Mountain Chickadees nest primarily in conifer forests from the low foothills to near tree line. About 20% of nests are in aspen woodlands. They excavate their own nest cavities and stuff them with bark, moss, and animal fur. Recent studies show that chickadees have complex languages, with dozens of different call sequences used to indicate varying degrees of danger and even name individual predators. - Conservation: These human-tolerant cavity-nesters seem to be thriving throughout the mountains of Colorado, though fire suppression and removal of old or rotting trees has reduced nesting opportunities in many forests. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775309758-2TCXXSCWRV30ISOUJHW8/Bushtit.jpg Regional Birds - Bushtit (Copy) Bushtit - Status: Uncommon to fairly common year-round resident of shrublands in and near the foothills. - Populations: Considered rare in Boulder County until quite recently, Bushtits have moved up into our foothills shrublands from the south, expanding their documented nesting range northward by at least 100 miles. In March they begin working on pendulous, oriole-like nests, which they hang from shrubs or small trees. Throughout the nesting process, pairs accept assistance from other adults and juveniles in raising young. - Conservation: Bushtits breed from southern British Columbia, southern Idaho, and Wyoming south to Guatemala. In Colorado highest densities of nesting pairs occur in piñon/juniper woodlands in the western valleys. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775320443-B71H80ISL2BFIFG5FNVA/RedBreastedNuthatch.jpg Regional Birds - Red-breasted Nuthatch (Copy) Red-breasted Nuthatch - Status: Fairly common year-round inhabitant of mountain conifer forests. - Populations: These vocal and colorful cavity-nesters breed primarily in conifer forests and aspen groves from the foothills to treeline. They wander throughout the mountains seeking out abundant conifer cone crops. - Conservation: Red-breasted Nuthatches nest from southeastern Alaska across southern Canada to the northern United States, including most of the western mountain ranges. While forest management has reduced the availability of snags for nesting in many areas, invasion of mature aspen forests by conifers has created near ideal nesting habitat, since these nuthatches typically forage in conifers but may prefer to excavate their nest cavities in aspens. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775329920-9A05SZ0P5Q2ZHN2CZZ8F/WhiteBreastedNuthatch.jpg Regional Birds - White-breasted Nuthatch (Copy) White-breasted Nuthatch - Status: Fairly common year-round resident of conifer forests, aspen groves, and plains riparian woodlands. - Populations: These relatively cosmopolitan nuthatches lay their eggs in cracks or woodpecker holes in conifers, aspens, and even cottonwoods, from the plains to around 10,000 feet. Inside the cavity, they construct a nest consisting of a layer of bark strips, a layer of dried earth or mud, and some animal fur. - Conservation: White-breasted nuthatches nest up to 10,000 feet virtually wherever there are trees of some kind--across southern Canada, the lower 48 states, and south to southern Mexico. In Colorado only a few pairs nest on the eastern plains, with highest nesting concentrations occurring in the foothills and lower mountains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775341028-PVSE03WHDGLRMYURB2CQ/PygmyNuthatch.jpg Regional Birds - Pygmy Nuthatch (Copy) Pygmy Nuthatch - Status: Common year-round resident in ponderosa pine forests. - Populations: Considered an "indicator species" of ponderosa pine woodlands and forests, Pygmy Nuthatches typically excavate their own nest cavities in ponderosas or other pines. They feed primarily on insects gleaned from the outer needles and twigs of the pines, often dangling upside down as they forage. - Conservation: These habitat specialists live year-round in pine forests from British Columbia to southern Mexico. This means that considerable numbers probably have occupied Colorado for only about 10,000 years, as ponderosa pines did not appear here until after the last ice age. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775352648-GJYG4SOHLPIZHLXJQLDM/BrownCreeper.jpg Regional Birds - Brown Creeper (Copy) Brown Creeper - Status: Fairly common year-round resident of mountain conifer forests, aspen groves, and plains riparian woodlands. - Populations: Listen for the very high-pitched, shrill calls of these active foragers as they spiral their way up conifer tree trunks from the lower foothills to the high mountains. They feed on spiders, beetles, moths, and other insects. Brown Creepers suspend hammock-like nests behind pieces of bark peeling away from dead or dying conifers. In winter look and listen for them in cottonwoods along prairie streams. - Conservation: Brown Creepers breed throughout most of North America, but usually in modest numbers. They may do best in mature to old-growth conifer forests containing lots of large, dead or dying trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777938652-5B9PM4EVFL14PBV5CB56/RockWren.jpg Regional Birds - Rock Wren (Copy) Rock Wren - Status: Fairly common summer resident in rocky areas from the foothills to alpine tundra. - Populations: These vocal, acrobatic wrens nest primarily in rocky areas, from the low foothills all the way up to the tundra. For unknown reasons, they build pebble trails across the rocks to their nests, which are constructed in rock crevices from twigs, grasses, wool, feathers, and plant material. - Conservation: Rock Wrens nest across western North America from southern Canada clear south to Central America. Breeding Bird Survey data indicate steady declines in their populations, especially in eastern Colorado. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777948301-KDSWDWPL6LA13V8UWFE0/CanyonWren.jpg Regional Birds - Canyon Wren (Copy) Canyon Wren - Status: Fairly common year-round resident in cliffy areas, primarily in the foothills. - Populations: These sweet-singing wrens nest almost exclusively on cliff faces, especially in the foothills. From February through August, their sad, descending songs are hard to miss in canyons of the Boulder Mountain Park. They attach their nests to overhanging ledges or rock faces, sallying forth to glean insects and spiders from the rock. - Conservation: In Colorado Canyon Wrens nest from 3900 feet to 8500 feet, and overall, they breed from the Rocky Mountain foothills to British Columbia and south to Chiapas. Since they nest in locations inaccessible to most humans (except rock climbers), their nesting populations face few threats. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777960820-MRU5LE1GGLREYLX4AIDU/HouseWren.jpg Regional Birds - House Wren (Copy) House Wren - Status: Very common summer resident in shrubby areas from the plains to the mid-mountains. - Populations: These secondary cavity-nesters breed wherever there is dense shrub vegetation, from the plains to around 10,000 feet. A single male constructs multiple stick nests in a tree cavity or building ledge, perhaps hoping to impress a female or to divert the attention of predators from the chosen nest. Their rich, bubbly song, though difficult for beginning birders to categorize, is unmistakable once learned. - Conservation: House Wrens breed throughout North and South America, and they are among the most abundant breeding birds in Colorado. Breeding numbers have increased in Boulder County where cattle have been removed from foothill shrublands and where fires or logging have opened up conifer forests and created more snags for nesting. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777971502-8TUCD4WZ715M4N327UG7/MarshWren.jpg Regional Birds - Marsh Wren (Copy) Marsh Wren - Status: Uncommon year-round resident in marshy areas of the plains. - Populations: Marsh Wrens are new arrivals to Boulder County, having been reported nesting here for the first time during the 2000s. Highly aggressive males attach multiple, globular nests to cattails or other marsh vegetation, and they destroy nearby nests of blackbirds and other Marsh Wrens. They accomplish all this well racing up and down the cattails and singing energetically; in fact, a single male may have a repertoire of more than 100 song phrases. - Conservation: Never common in Colorado, Marsh Wrens may have expanded their nesting range recently as cattail marshes matured around prairie reservoirs and gravel ponds. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777998403-O2A1LRMPUCBKGV9MVT2G/BlueGrayGnatcatcher.jpg Regional Birds - Blue-gray Gnatcatcher (Copy) Blue-gray Gnatcatcher - Status: Fairly common summer resident in shrubby areas and open woodlands of the foothills. - Populations: These perky little insectivores breed in piñon-juniper woodlands throughout southern and western Colorado and in ponderosa pine woodlands along the Front Range foothills. Beginning in April, they construct artful cup nests from grass, moss, feathers, fur, and lichens in the fork of two small branches or sometimes in a saddle of a horizontal limb. - Conservation: Populations have increased and expanded northward in North America during recent decades. Along the Colorado Front Range, increased shrub density as cattle were removed from the foothills may have contributed to this range expansion. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777983365-VDY9E7RKZB44GP9KNVQM/GoldenCrownedKinglet.jpg Regional Birds - Golden-crowned Kinglet (Copy) Golden-crowned Kinglet - Status: Uncommon to fairly common summer resident of subalpine conifer forests and winter resident of foothills and mountains conifer forests. - Populations: Without being alert to the extremely high-pitched "see-see-see-chick-a-dee song of this tiny insectivore, you're likely to miss it as it hops around in conifer treetops in the subalpine life zone. These kinglets thrive in mature to old-growth Engleman spruce/subalpine fir forests, where they weave hanging nests from bark, lichens, mosses, webs, and fur. - Conservation: Conservation of mature subalpine forests throughout the high country of Boulder County and elsewhere has probably contributed to modest increases in Golden-crowned Kinglet nesting populations in recent decades. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592778018663-VKEE14C0QWTQJSYU5EKW/RubyCrownedKinglet.jpg Regional Birds - Ruby-crowned Kinglet (Copy) Ruby-crowned Kinglet - Status: Common year-round resident, primarily of mountain conifer forests. - Populations: The lilting, complex songs of these acrobatic kinglets fill our mountain conifer forests from May through August. Nests are constructed from mosses, lichens, and other plant material and tucked into crevices in the bark of conifers, making them difficult to locate. - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592778030164-RIVY03VE202TAO3FHLE0/AmericanDipper.jpg Regional Birds - American Dipper (Copy) American Dipper - Status: Fairly common year-round resident of streams from the base of the foothills to the alpine tundra. - Populations: The joyful, complex songs of American Dippers echo off foothill and mountain canyon cliffs throughout the year. Pairs defend nesting territories in summer and lower-elevation foraging territories in winter. They dive into the rushing water, using their wings to shoot through the current as they snatch insect larvae from under rocks. Listen and look for them from White Rocks on the plains to Fourth of July Mine on South Arapaho Peak. - Conservation: American Dippers forage in mountain, coastal, and desert streams from Alaska to Panama. Some breeding pairs have benefited from construction of bridges and nest boxes over and along streams; however, channelization of streams and degradation of streamside embankments have reduced the number of natural nesting sites. Pollution from mines has devastated insect populations in some nesting areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776457962-SLVIJRZYRBV2NTEUOGHZ/EasternBluebirdMale.jpg Regional Birds - Eastern Bluebird (m) (Copy) Eastern Bluebird (m) - Status: Uncommon migrant; rare summer resident in the foothills and on the plains. - Populations: Populations: While Eastern Bluebirds are occasionally reported on the Boulder Christmas Bird Count, only two Boulder County nesting sites have been documented recently, both at the base of the foothills. Relative newcomers to Colorado, these cavity-nesters have followed the spread of deciduous woodlands and orchards westward across the western plains. - Conservation: North American bluebird populations plummeted throughout the first two-thirds of the 20th century as introduced European Starlings and House Sparrows appropriated nest sites. Pesticide use on farms and removal of dead trees also harmed nesting populations. Conservation efforts, combined with creation of thousands of bluebird nest box trails throughout the continent, have contributed to a more than doubling of nesting populations during the past 50 years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776467574-7R6H0BFOVQCHD37VKIWF/EasternBluebirdFemale.jpg Regional Birds - Eastern Bluebird (f) (Copy) Eastern Bluebird (f) - Status: Uncommon migrant; rare summer resident in the foothills and on the plains. - Populations: Populations: While Eastern Bluebirds are occasionally reported on the Boulder Christmas Bird Count, only two Boulder County nesting sites have been documented recently, both at the base of the foothills. Relative newcomers to Colorado, these cavity-nesters have followed the spread of deciduous woodlands and orchards westward across the western plains. - Conservation: North American bluebird populations plummeted throughout the first two-thirds of the 20th century as introduced European Starlings and House Sparrows appropriated nest sites. Pesticide use on farms and removal of dead trees also harmed nesting populations. Conservation efforts, combined with creation of thousands of bluebird nest box trails throughout the continent, have contributed to a more than doubling of nesting populations during the past 50 years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776480724-OV6JTRE070P7991JLVYN/WesternBluebirdMale.jpg Regional Birds - Western Bluebird (m) (Copy) Western Bluebird (m) - Status: Fairly common summer resident in the foothills; rare winter resident. - Populations: These beautiful cavity-nesters favor open ponderosa pine woodlands throughout the western half of the state. In Boulder County several hundred pairs nest in bluebird boxes at Walker Ranch, Betasso Preserve, and other foothills parks, where they frequently supplant nesting Mountain Bluebirds. Bluebirds sally forth from perches to snatch insects from the air. - Conservation: Listed as "rare and declining" in Boulder County as late as 1990, Western Bluebirds have made a spectacular recovery. However, they remain dependent on artificial nest boxes, especially as forestry practices still include mass cutting of dead snags. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776491920-B4CX5O01VUIM3FUGLQHN/WesternBluebirdFemale.jpg Regional Birds - Western Bluebird (f) (Copy) Western Bluebird (f) - Status: Fairly common summer resident in the foothills; rare winter resident. - Populations: These beautiful cavity-nesters favor open ponderosa pine woodlands throughout the western half of the state. In Boulder County several hundred pairs nest in bluebird boxes at Walker Ranch, Betasso Preserve, and other foothills parks, where they frequently supplant nesting Mountain Bluebirds. Bluebirds sally forth from perches to snatch insects from the air. - Conservation: Listed as "rare and declining" in Boulder County as late as 1990, Western Bluebirds have made a spectacular recovery. However, they remain dependent on artificial nest boxes, especially as forestry practices still include mass cutting of dead snags. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776501228-TN80VQO3X6WVRZ2QJWUL/MountainBluebirdMale.jpg Regional Birds - Mountain Bluebird (m) (Copy) Mountain Bluebird (m) - Status: Fairly common summer resident and migrant; uncommon winter resident. - Populations: These habitat generalists nest in piñon-juniper woodlands, ponderosa pine woodlands, spruce-fir forests, aspen groves, riparian woodlands, and rural residential areas throughout the western two-thirds of the state. In addition to woodpecker holes and artificial nest boxes, they nest on cabin ledges and in holes in building walls, abandoned Cliff Swallow nests, cattle chutes, ski lift towers, and basketball standards. - Conservation: North American populations have rebounded during the past few decades as bluebird trails were created and forestry practices evolved toward retaining more dead trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776510761-TIXOQSC9WANWGZKGP9SF/MountainBluebirdFemale.jpg Regional Birds - Mountain Bluebird (f) (Copy) Mountain Bluebird (f) - Status: Fairly common summer resident and migrant; uncommon winter resident. - Populations: These habitat generalists nest in piñon-juniper woodlands, ponderosa pine woodlands, spruce-fir forests, aspen groves, riparian woodlands, and rural residential areas throughout the western two-thirds of the state. In addition to woodpecker holes and artificial nest boxes, they nest on cabin ledges and in holes in building walls, abandoned Cliff Swallow nests, cattle chutes, ski lift towers, and basketball standards. - Conservation: North American populations have rebounded during the past few decades as bluebird trails were created and forestry practices evolved toward retaining more dead trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776519444-S23CABBG6T99CA6VRIHB/TownsendsSolitaire.jpg Regional Birds - Townsend's Solitaire (Copy) Townsend's Solitaire - Status: Common year-round resident in foothills and mountains. - Populations: Most easily located by their upward-spiraling song, Swainson's thrushes breed throughout the mountains of Colorado, primarily in willow thickets and aspen groves, but also in open conifer forests containing shrubbery. They build their nests in thick vegetation close to the ground. Migrants can be heard singing on the plains of Boulder County well into June. - Conservation: Townsend's Solitaires nest throughout the western half of Colorado, and their North American breeding range includes mountain ranges from Alaska to New Mexico. Little is known about nesting population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776535489-L08X5SEBO5NAW23OFCMF/SwainsonsThrush.jpg Regional Birds - Swainson's Thrush (Copy) Swainson's Thrush - Status: Fairly common summer resident in mountain willow carrs. - Populations: Most easily located by their upward-spiraling song, Swainson's thrushes breed throughout the mountains of Colorado, primarily in willow thickets and aspen groves, but also in open conifer forests containing shrubbery. They build their nests in thick vegetation close to the ground. Migrants can be heard singing on the plains of Boulder County well into June. - Conservation: Among our most commonly observed migrants during late spring, Swainson's Thrushes breed throughout forested regions of Canada, Alaska, New England, and the western states. Due to the remoteness of most nesting locations, little is known about population trends. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776545468-8IJJK61EV8GSPLZ8KKDW/HermitThrush.jpg Regional Birds - Hermit Thrush (Copy) Hermit Thrush - Status: Fairly common summer resident in mountain conifer forests. - Populations: The ethereal, flute-like songs of these reclusive thrushes haunt conifer forests from the foothills to the high mountains. Pairs generally place their nest in a shrub or on a tree trunk close to the ground, and they feed their young a diet of insects, spiders, earthworms, sow bugs, snails, and wild currants. - Conservation: Found primarily in open forests in the East and closed-canopy conifer forests in the West, Hermit Thrushes breed from Newfoundland to central Alaska and south to the Great Lakes area, New Mexico, and California. Clear-cutting of conifer forests has decimated nesting populations in parts of the West. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776555680-N4ONOQWI0EI3W9130YZ6/AmericanRobin.jpg Regional Birds - American Robin (Copy) American Robin - Status: Abundant year-round resident from the plains to the high mountains. - Populations: These adaptive omnivores nest from the plains to the high subalpine and thrive around human settlements, where they feast on earthworms, insects, and wild and domestic fruits. Poisoning of robins by DDT that accumulated on tree leaves and was then ingested by earthworms was reported by Rachel Carson and contributed to our awareness of the toxicity of this lethal pesticide. - Conservation: Robins thrive throughout Colorado and most of North America, and their populations are probably increasing in urban areas and along prairie streams, where deciduous trees provide nesting sites and lawns and meadows provide foraging areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776564922-G571KJS3W3HIWR00Y9BI/GrayCatbird.jpg Regional Birds - Gray Catbird (Copy) Gray Catbird - Status: Fairly common summer resident in foothills shrublands and plains riparian woodlands. - Populations: Catbirds typically nest in dense foliage near the ground, so in Boulder County they're most often found in foothills shrublands and in shrubby areas along prairie streams. They sing their scratchy, complex songs from prominent perches overlooking nesting areas. - Conservation: Numbers have increased in areas of the foothills as shrub vegetation has proliferated after cattle were removed from open space properties. On the plains, shrub vegetation is just not dense enough in most places, even along streams, to facilitate nesting. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776574451-2LYYIO69GTPC7J8ZHW7N/NorthernMockingbird.jpg Regional Birds - Northern Mockingbird (Copy) Northern Mockingbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776585235-3TYY9OKYOAQUXM1GSXLJ/SageThrasher.jpg Regional Birds - Sage Thrasher (Copy) Sage Thrasher - Status: Uncommon to rare resident and migrant in in shrub thickets in the foothills and on the plains. - Populations: Their affinity for shrublands makes these conspicuous singers fairly common in sagebrush areas of northwestern Colorado, the western valleys, and the San Luis Valley but rare in Boulder County. Look for them, especially during spring migration and late summer, at Rabbit Mountain and Doudy Draw. - Conservation: Breeding Bird Survey data suggest that numbers of nesting pairs have increased dramatically in Colorado, perhaps as a result of improved grazing practices in sagebrush uplands. In Boulder County, breeding Sage Thrashers have all but disappeared, with only a couple of nesting observations reported during the past two decades. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776595768-RQC81H70TU9ZDA2VLM3T/BrownThrasher.jpg Regional Birds - Brown Thrasher (Copy) Brown Thrasher - Status: Rare summer resident in plains riparian woodlands. - Populations: Among our most talented mimic thrushes, Brown Thrashers can sing hundreds of distinct phrases from conspicuous perches in deciduous woodlands and shelterbelts on the plains. A decidedly eastern species, they just make it into Boulder County, where pairs have been observed nesting at Rabbit Mountain and south of Eldorado Springs. - Conservation: Breeding throughout the eastern United States and southern Canada, Brown Thrashers have gradually extended their nesting range westward as deciduous woodlands and shrublands developed along prairie streams and in rural shelterbelts. However, Breeding Bird Survey data show a substantial drop in North American populations during the last three decades of the 20th century. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224659729-3YEWBPDDAD7AJQ718HNB/EuropeanStarling.jpg Regional Birds - European Starling (Copy) European Starling - Status: Very common year-round resident, especially in and around towns; plains to high mountain communities. - Populations: Ubiquitous wherever human habitations occur but less common in more natural areas, such as the Boulder Mountain Park and Indian Peaks Wilderness. First introduced from Europe into North America during the 19th century and now probably our most common bird, preying on songbird nests and displacing cavity-nesting birds. - Conservation: Breeds in North America from Alaska to northern Mexico and Florida. Populations stable or increasing throughout most of North American breeding range, though numbers have declined in Great Britain. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224677407-KNT98QN4CK43K2UJYBOT/AmericanPipit.jpg Regional Birds - American Pipit (Copy) American Pipit - Status: Fairly common summer resident on the tundra; fairly common to uncommon migrant on the plains. - Populations: These sparrow-sized songbirds with shorebird-like habits nest on the alpine tundra from New Mexico north to Alaska, Baffin Island, and Greenland. Often seen during migration on wetter areas of the plains, they typically arrive in the tundra in April and some stay into October. - Conservation: Nesting populations appear to be stable, though few data are available. Ski area construction and other disturbances in the alpine tundra have fragmented nesting habitat in Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224697597-QP4UDN7EKI9UCWP3DIU8/BohemianWaxwing.jpg Regional Birds - Bohemian Waxwing (Copy) Bohemian Waxwing - Status: Irregular winter resident, plains to mid-elevation mountains. - Populations: A winter visitor to Boulder County, abundant during some years and not present during others. During years with above-average fall/winter fruit crops, flocks of hundreds will descend on junipers and mountain-ash trees, forming berry brigades to pass fruits from one beak to another. They nest exclusively in western Canada and Alaska. - Conservation: Because of the remoteness of their nesting areas in northern boreal forests, little is known about population trends. Here in Boulder County, urban planting of mountain-ashes and other trees that bear fruit deep into winter has probably attracted wandering flocks. Photo © 2013, Mike Milicia https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224707807-7Z0H9A5UA4XGJS25LQ3D/CedarWaxwing.jpg Regional Birds - Cedar Waxwing (Copy) Cedar Waxwing - Status: Uncommon summer resident on the plains; fairly common to uncommon year-round resident, plains and foothills. - Populations: These beautiful and somewhat secretive waxwings nest in late summer in deciduous woodlands of the plains and lower foothills. Look for them along Coal Creek, South Boulder Creek, St. Vrain Creek, and other streams cutting down through the hills and at Sawhill and Walden Ponds. During some years, large flocks may overwinter. - Conservation: Populations appear secure throughout most breeding areas in the northern United States and southern and central Canada, with increases reported on the western plains, where the spread of deciduous trees has increased foraging and nesting opportunities. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225328496-21Y2B8GLADJAPJXJA1C3/OrangeCrownedWarbler.jpg Regional Birds - Yellow-crowned Warbler (Copy) Yellow-crowned Warbler - Status: Fairly common migrant, plains, foothills, and mountains. - Populations: One of the earliest migrating warblers to appear in spring, often heard singing in riparian and shrubby areas in the foothills by late April. Nests in brushy woodlands and forest edges from New Mexico and Colorado (west slope only) and California north to Alaska and Newfoundland. - Conservation: Breeding Bird Survey data indicated a 1.9% decline throughout the United States from 1966-2012. Encroachment of human habitations into shrubby areas and forest edges may have reduced nesting habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225342606-XUXBEEGJC4LLFEKA8E56/VirginiasWarbler.jpg Regional Birds - Virginia's Warbler (Copy) Virginia's Warbler - Status: Fairly common summer resident of open forests, foothills and mountains. - Populations: One of our most common warblers, though more often heard than seen as it sings (a weak, lazy, "see-see-see-see-see-see, see-see, see"--descending slightly and then rising at the end) from perches in conifers in open forests of the foothills and low mountains. Nests on the ground under shrubs throughout the southern Rocky Mountains and Great Basin region. - Conservation: Doing very well in Boulder County, where increased shrub growth in the foothills after the removal of grazing cattle has enriched nesting habitat. In contrast, fire suppression in mountain conifer forests has reduced nesting habitat by suppressing shrub growth. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225354603-ZNETSZYTKGRE4RC721BH/YellowWarbler.jpg Regional Birds - Yellow Warbler (Copy) Yellow Warbler - Status: Common summer resident in riparian woodlands; plains, foothills, and mountains. - Populations: Common in deciduous woodlands from the plains to about 8500 feet. Easily identified by its breathy, descending "sweet-sweet-sweet, I'm so very sweet" song, often delivered from high in a cottonwood. Nests throughout North America from Alaska south to central Mexico. - Conservation: Boulder County nesting populations have thrived as deciduous woodlands proliferate along prairie streams and in urban settlements. Breeding Bird Survey data indicate that populations throughout North America remain stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225385273-F109ALKL9QC8TJGOTEJ0/YellowRumpedWarbler.jpg Regional Birds - Yellow-rumped Warbler (Copy) Yellow-rumped Warbler - Status: Common summer resident in foothill and mountain conifer forests. - Populations: These colorful mountain warblers nest in conifer forests at virtually all elevations, from central Mexico north to Alaska and Newfoundland. Their Boulder County nesting range overlaps in the foothills and lower mountains with that of Virginia's warbler, whose song they may "adopt," sometimes rendering identification by ear challenging. - Conservation: Abundant in conifer forests from 7500-11,000 ' and probably our most common Boulder County warbler. Nesting populations appear stable throughout most of the mountains of western North America. Still one of our most common migrants on the plains and in the foothills in May and September. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225397420-M9UYILWANW0ZI5AV9FEE/TownsendsWarbler.jpg Regional Birds - Townsend's Warbler (Copy) Townsend's Warbler - Status: Uncommon migrant, primarily in mountain forests. - Populations: Observed primarily in August and September as adults and fledglings move southward through mountain forests toward Mexico and Central America. Nests in conifer forests of northwestern North America, from Wyoming to Alaska. - Conservation: Breeding Bird Survey results indicate that North American nesting populations are stable. Number observed in Colorado during migration probably depends in part on availability of insects in mountain conifer forests. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225409210-734ESYQ8EQB832NVN5DP/AmericanRedstart.jpg Regional Birds - American Redstart (Copy) American Redstart - Status: Rare migrant, primarily in plains riparian woodlands. - Populations: Nests primarily in deciduous forests and second-growth woodlands from Florida north to Newfoundland, Yukon Territory, and Southeast Alaska. Each spring and early summer, a few males are heard singing in foothills deciduous woodlands of Boulder County, but nesting has never been documented here. Most easily found by the male's distinctive song, a series of high, thin notes usually followed by a down-slurred note. - Conservation: Since they thrive in open deciduous habitats, American redstarts have benefited from clearing of some forest areas. However, loss of deciduous woodlands throughout much of eastern North America has impacted nesting populations, and Breeding Bird Survey data show a statistically significant decline of 1.5%/year throughout the United States from 1966-2012. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225422095-OUV3VSN5J5VDTFP1MJFJ/Ovenbird.jpg Regional Birds - Ovenbird (Copy) Ovenbird - Status: Uncommon summer resident in foothills canyons. - Populations: Pairs use leaf litter to build their oven-shaped nests on the ground, from the southeastern United States westward to the Rockies and north into central Canada. Though not uncommon in Gambel oak woodlands of the southern Front Range, nesting pairs appear rare in Northern Colorado, where absence of oak leaf litter makes nest building a challenge. Here in Boulder County we observe several singing males each spring and early summer but have never documented nesting. - Conservation: North American populations appear to be stable. Numbers appear to have increased in western Nebraska and along the Colorado Front Range as deciduous tree and shrub growth has proliferated in canyon areas. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225433920-TAUJXCENAYVZFYZCHGKB/MacGillivraysWarbler.jpg Regional Birds - MacGillivray's Warbler (Copy) MacGillivray's Warbler - Status: Fairly common summer resident in foothills riparian woodlands and mountain willow carrs. - Populations: Listen for the short (usually seven notes or fewer), churry warbles of these ground-nesters along foothill and mountain streams from 6500-10,500'. Their call is a sharp, harsh tsik, similar but slightly lighter than that of dark-eyed juncos. They nest throughout the mountains of western North America wherever dense undergrowth is available. - Conservation: Ski area construction and other disturbances of mountain willow carrs and montane shrublands have reduced available nesting habitat in Colorado. Breeding Bird Survey data indicate a statistically significant 0.8%/year decline in populations throughout the United States from 1966-2012. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225447065-7MMMEZLOTV82P033K1EP/CommonYellowthroat.jpg Regional Birds - Common Yellowthroat (Copy) Common Yellowthroat - Status: Common summer resident in marshes and willow carrs, plains to mid-elevation mountains. - Populations: The sweet, loud "wichity, wichity, wichity," song of these bright yellow and brown warblers resonates in cattail marshes and other wetlands on the plains throughout late spring and early summer. Nests on the ground in dense vegetation. - Conservation: Proliferation of cattail marshes around gravel mining areas has probably benefited these marsh-nesting warblers in Boulder County, though most of the original wetlands where they nested historically have been destroyed. Breeding Bird Survey data indicate a 1.0%/year decline throughout North America from 1966-2012. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225461725-E94FOV6AYYRG72U4YGKS/WilsonWarbler.jpg Regional Birds - Wilson's Warbler (Copy) Wilson's Warbler - Status: Fairly common summer resident in wet mountain forests and willow carrs. - Populations: These active, yellow-faced warblers nest in dense bogs and willow thickets, primarily above 8500'. Their song is a series of chee notes, generally on the same pitch and slower than the song of yellow warblers. They nest in boreal wetlands of North America from Colorado and California north to Alaska and Northwest Territories, and across central and northern Canada to Newfoundland. - Conservation: Breeding Bird Survey data indicate a 1.8%/year decline throughout North America from 1966-2012. Destruction and fragmentation of mountain willow carrs by various human activities can reduce nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225472706-249IGLI3D1HRW76WOCUO/Yellow-BreastedChat.jpg Regional Birds - Yellow-breasted Chat (Copy) Yellow-breasted Chat - Status: Common summer resident, plains and foothills shrublands. - Populations: These medium-sized, thick-billed insectivores in the genus Icteria were once considered to be warblers, but are probably best placed in a group all their own. Males perch prominently in foothill shrubs, emitting an unrelenting stream of whistles, grunts, squawks, chattering clucks, and rattles. Males often sing right through the night. - Conservation: Nesting populations have probably increased at the base of the Boulder County foothills as grazing cattle were removed from shrubby areas. Breeding Bird Survey data indicate a 0.6%/year decline throughout North America from 1966-2012. Photo © 2013, Ken Cook https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593228989245-KBXGEX9TB9O45PWI09DY/GreenTailedTowhee.jpg Regional Birds - Green-tailed Towhee (Copy) Green-tailed Towhee - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229001589-M6HLVUABN8THOUVZVRCK/SpottedTowhee.jpg Regional Birds - Spotted Towhee (Copy) Spotted Towhee - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229014917-13VIBBEC05Z6T7JZCQHE/AmericanTreeSparrow.jpg Regional Birds - American Tree Sparrow (Copy) American Tree Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229027425-AVHHO60KIMKG3RRIIRH3/ChippingSparrow.jpg Regional Birds - Chipping Sparrow (Copy) Chipping Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229042660-XN49WH0CB0GITTSXA8W9/BrewersSparrow.jpg Regional Birds - Brewer's Sparrow (Copy) Brewer's Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229055350-NPBPAPCLIQN7GW3P9228/VesperSparrow.jpg Regional Birds - Vesper Sparrow (Copy) Vesper Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229065901-OOZBPVMZGG8NFPKB9ZNY/LarkSparrow.jpg Regional Birds - Lark Sparrow (Copy) Lark Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229076379-BGVI7KKPG47K99FWEUVH/LarkBunting.jpg Regional Birds - Lark Bunting (Copy) Lark Bunting - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229086265-AWTHTKV4NZYRRASZL3FD/SavannahSparrow.jpg Regional Birds - Savannah Sparrow (Copy) Savannah Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229097475-CDMJW85731KYVTF4NSZ4/GrasshopperSparrow.jpg Regional Birds - Grasshopper Sparrow (Copy) Grasshopper Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229113680-AOOONVQPHOIKKLVTDC1K/FoxSparrow.jpg Regional Birds - Fox Sparrow (Copy) Fox Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229126748-220E7A9GCT3P0STNYRRI/SongSparrow.jpg Regional Birds - Song Sparrow (Copy) Song Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229140104-VHVH5HVNN3INSRPZDMDJ/LincolnSparrow.jpg Regional Birds - Lincoln's Sparrow (Copy) Lincoln's Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229150274-D6MO84C96DXUEBTAGMPF/WhiteCrownedSparrow.jpg Regional Birds - White-crowned Sparrow (Copy) White-crowned Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229161680-GPK5NTS031Z5EDDMR2LQ/DarkEyedJunco.jpg Regional Birds - Dark-eyed Junco (Copy) Dark-eyed Junco - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593264620431-T2JS51JK5BAS5O3VOC41/WesternTanager.jpg Regional Birds - Western Tanager (m) (Copy) Western Tanager (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263066103-HQE6X2YR9WZU6Q0RQFVP/WesternTanagerFemale.jpg Regional Birds - Western Tanager (f) (Copy) Western Tanager (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263081477-YQ0EXM9TO7RSAKOY1Z9U/Rose-breastedGrosbeak.jpg Regional Birds - Rose-breasted Grosbeak (Copy) Rose-breasted Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263094722-DBN5PNY970AQO88NM4AX/BlackHeadedGrosbeakMale.jpg Regional Birds - Black-headed Grosbeak (m) (Copy) Black-headed Grosbeak (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263138297-SOSEOWRZ7SKTVGO4AZ2T/BlueGrosbeak.jpg Regional Birds - Blue Grosbeak (Copy) Blue Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263152089-T9UMMRL883M2LVP4FPSQ/LazuliBunting.jpg Regional Birds - Lazuli Bunting (m) (Copy) Lazuli Bunting (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263163884-PMQC1EL8RJJ50MO0402L/LazuliBuntingFemale.jpg Regional Birds - Lazuli Bunting (f) (Copy) Lazuli Bunting (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Ken Cook https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263176642-XDBTNRZE6NMWXGKXKD46/IndigoBunting.jpg Regional Birds - Indigo Bunting (Copy) Indigo Bunting - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263190107-MJ6GNMZEBE7V904FKGPY/Bobolink.jpg Regional Birds - Bobolink (Copy) Bobolink - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263203675-DMC3FRFWRYSDKJORQHNA/RedWingedBlackbirdMale.jpg Regional Birds - Red-winged Blackbird (m) (Copy) Red-winged Blackbird (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263214085-KXTE2PLTXFME0SVCMTCJ/RedWingedBlackbirdFemale.jpg Regional Birds - Red-winged Blackbird (f) (Copy) Red-winged Blackbird (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263224230-OIYKOBGWTAWZHTHESSTI/WesternMeadowlark.jpg Regional Birds - Western Meadowlark (Copy) Western Meadowlark - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263236327-GQ8JWEE1E1S40697RQHQ/YellowHeadedBlackbird.jpg Regional Birds - Yellow-headed Blackbird (Copy) Yellow-headed Blackbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263246801-O9U8DKXHTKA1ZETPMH00/BrewersBlackbird.jpg Regional Birds - Brewer's Blackbird (Copy) Brewer's Blackbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263258698-JV2KIHSMQ5MBYEQ1UFCK/CommonGrackle.jpg Regional Birds - Common Grackle (Copy) Common Grackle - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263270899-RIXCKRNEIW41V8MWTBVB/Great-tailedGrackle.jpg Regional Birds - Great-tailed Grackle (Copy) Great-tailed Grackle - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263280210-JS5PLDCV7IBIWYDXKO65/Brown-headedCowbird.jpg Regional Birds - Brown-headed Cowbird (Copy) Brown-headed Cowbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263290316-QM4V79042O3PNBG1TCCI/BullocksOrioleMale.jpg Regional Birds - Bullock's Oriole (m) (Copy) Bullock's Oriole (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263304425-5F2P5U4C2DD47ORJM0U4/OrchardOriole.jpg Regional Birds - Orchard Oriole (Copy) Orchard Oriole - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265265053-3BK6CQOB5Y4ZOXXDTPX3/Gray-CrownedRosyFinch.jpg Regional Birds - Gray-crowned Rosy Finch (Copy) Gray-crowned Rosy Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Ken Cook https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265280043-S6SAQ1P3V340YYR4NJAI/Brown-cappedRosyFinch.jpg Regional Birds - Brown-capped Rosy Finch (Copy) Brown-capped Rosy Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265293046-HBG00N507BJE4VNI3YPZ/PineGrosbeak.jpg Regional Birds - Pine Grosbeak (Copy) Pine Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265305447-M0G7HY1HDCVBQJY315K2/CassinsFinch.jpg Regional Birds - Cassin's Finch (Copy) Cassin's Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265316409-M6KM4NSVQP9WC7WYAKV5/HouseFinchMale.jpg Regional Birds - House Finch (m) (Copy) House Finch (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265329220-7CMPF52RHF9O518IE6TZ/HouseFinchFemale.jpg Regional Birds - House Finch (f) (Copy) House Finch (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265341848-W012NKC7T60N0NRV5TCL/RedCrossbillDuplicate.jpg Regional Birds - Red Crossbill (Copy) Red Crossbill - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265353076-ALU6JSZV1C0OZJI7DOAN/PineSiskin.jpg Regional Birds - Pine Siskin (Copy) Pine Siskin - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265364465-VJ2VXDGZCQI0ZAK43ID7/LesserGoldfinch.jpg Regional Birds - Lesser Goldfinch (Copy) Lesser Goldfinch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265376798-6VNH37W2Q0QEJC8TV3GN/AmericanGoldfinchMale.jpg Regional Birds - American Goldfinch (m) (Copy) American Goldfinch (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265393988-1QIJZP74MIM3JMHR0PXH/AmericanGoldfinchFemale.jpg Regional Birds - American Goldfinch (f) (Copy) American Goldfinch (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265405865-G2UXL6NJGEU4X7Z36G60/EveningGrosbeakMale.jpg Regional Birds - Evening Grosbeak (Copy) Evening Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265422271-P4DJ41V7HC2RO8D7A2HI/HouseSparrow.jpg Regional Birds - House Sparrow (Copy) House Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Kevin McCarthy https://www.kevinks.com/newsletters daily 0.75 2021-03-17 https://www.kevinks.com/habitat-hero daily 0.75 2020-06-25 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052631583-WAB7XUP3O3LI6KTXNNEY/ColoradoWildscapesCover-244x300.jpg Habitat Hero https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052594113-62MBFWMTFF3NX2X1APZW/habitat_hero_birdwatcher_garden_2_web.jpg Habitat Hero Artist rendering of the Habitat Hero Birdwatcher Garden in full bloom. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052563887-5STXL4HH1R8F4IMDR2N4/Swamp_milkweed_monarch_WikiCommons.jpg Habitat Hero Monarch on Milkweed https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052631583-WAB7XUP3O3LI6KTXNNEY/ColoradoWildscapesCover-244x300.jpg Habitat Hero https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052594113-62MBFWMTFF3NX2X1APZW/habitat_hero_birdwatcher_garden_2_web.jpg Habitat Hero Artist rendering of the Habitat Hero Birdwatcher Garden in full bloom. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052563887-5STXL4HH1R8F4IMDR2N4/Swamp_milkweed_monarch_WikiCommons.jpg Habitat Hero Monarch on Milkweed https://www.kevinks.com/habitat-wildlife-monitoring daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052175228-T2D2YT59WBX7T123OKZX/BrownCreeperHabitatHero.jpg Habitat & Wildlife Monitoring Brown Creeper https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052210084-VAX4ERUE3Q9WSADBG9GK/WhiteThroatedSwiftHabitatHero.jpg Habitat & Wildlife Monitoring White-throated Swift https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052175228-T2D2YT59WBX7T123OKZX/BrownCreeperHabitatHero.jpg Habitat & Wildlife Monitoring Brown Creeper https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593052210084-VAX4ERUE3Q9WSADBG9GK/WhiteThroatedSwiftHabitatHero.jpg Habitat & Wildlife Monitoring White-throated Swift https://www.kevinks.com/nest-box-monitoring daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593040029543-EI598WFICGS8HVW4S3EQ/MountainBluebirdMale.jpg Nest Box Monitoring Male Mountain Bluebird. Blue feathers results from their structure, rather than from pigment. Because of this, the apparent color varies with the lighting. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593040029543-EI598WFICGS8HVW4S3EQ/MountainBluebirdMale.jpg Nest Box Monitoring Male Mountain Bluebird. Blue feathers results from their structure, rather than from pigment. Because of this, the apparent color varies with the lighting. https://www.kevinks.com/wildlife-inventories daily 0.75 2020-06-24 https://www.kevinks.com/contact-us daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593098477712-923HMN1D88BZT0244LDC/YellowWarbler%2BSinging.jpg Contact Us https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593098477712-923HMN1D88BZT0244LDC/YellowWarbler%2BSinging.jpg Contact Us https://www.kevinks.com/nature-net daily 0.75 2020-06-26 https://www.kevinks.com/jaseys-bird-house daily 0.75 2020-06-27 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593218281204-S864PKNKCHRX5KOLGM6E/GreatBlueHeron_JaseysBirdHouse.png Jasey's Bird House https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593218281204-S864PKNKCHRX5KOLGM6E/GreatBlueHeron_JaseysBirdHouse.png Jasey's Bird House https://www.kevinks.com/event-types daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333792167-KDBSCIGT66AZGOFTSBW9/MembershipImage.jpg Event Types https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333792167-KDBSCIGT66AZGOFTSBW9/MembershipImage.jpg Event Types https://www.kevinks.com/register-for-interludes-with-nature daily 0.75 2020-06-29 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593395361596-LQE8IIGAW1E4SW769AO8/Browns-Park-National-Wildlife-Refuge.jpg Register for Interludes with Nature https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593395385513-70MH4B3P01WSGNKJVQRV/BurrowingOwls.jpg Register for Interludes with Nature https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593395361596-LQE8IIGAW1E4SW769AO8/Browns-Park-National-Wildlife-Refuge.jpg Register for Interludes with Nature https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593395385513-70MH4B3P01WSGNKJVQRV/BurrowingOwls.jpg Register for Interludes with Nature https://www.kevinks.com/advocacy daily 0.75 2021-03-17 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333814202-4QQBOFLTUS4LU8U0F6H0/MembershipImage.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004078177-590MRRFTHRGE6HDH62WO/Screen%2BShot%2B2020-09-04%2Bat%2B1.59.17%2BPM.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004254954-S1MGA1GX9RBBNCG0Q79B/MarshWren.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599250059644-ND8B525CHI9X5EWH77WQ/JohnKlatenbach.jpg Get Involved - Volunteer BCAS is looking for volunteers to help on conservation projects. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004126811-O5HOQHXU7U86KQ5OWIVC/BurrowingOwls.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599333814202-4QQBOFLTUS4LU8U0F6H0/MembershipImage.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004078177-590MRRFTHRGE6HDH62WO/Screen%2BShot%2B2020-09-04%2Bat%2B1.59.17%2BPM.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004254954-S1MGA1GX9RBBNCG0Q79B/MarshWren.jpg Get Involved https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1599250059644-ND8B525CHI9X5EWH77WQ/JohnKlatenbach.jpg Get Involved - Volunteer BCAS is looking for volunteers to help on conservation projects. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004126811-O5HOQHXU7U86KQ5OWIVC/BurrowingOwls.jpg Get Involved https://www.kevinks.com/award-winners daily 0.75 2021-03-17 https://www.kevinks.com/volunteer daily 0.75 2021-03-17 https://www.kevinks.com/education-activities daily 0.75 2021-03-18 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004814752-FYCJM7OIE8FC9L6LQ4NY/Group-300x199.png Education Activities - TeEn Naturalists Boulder County Audubon’s Teen Naturalist program offers middle and high school students the opportunity to explore many facets of the natural world and their interactions. The group participates in wildlife surveys (birds, bats, butterflies, etc.), BioBlitzes, nature photography workshops, and other outdoor activities. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1598970079841-CBQAM8V0H1DFQCUQZM6J/teenbanding-1024x683.jpg Education Activities - Teen Bird Camp Scholarships BCAS offers full scholarships to two summer ornithology camps for Boulder County area students: Hog Island Maine Birding Camp and American Birding Association Camp Colorado Birding Camp. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615997015300-0V5FALJZJ5C7Y7HPOSLH/PrarieDog-300x205.png Education Activities - eMovement Initiative [Something about the program] https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1616004814752-FYCJM7OIE8FC9L6LQ4NY/Group-300x199.png Education Activities - TeEn Naturalists Boulder County Audubon’s Teen Naturalist program offers middle and high school students the opportunity to explore many facets of the natural world and their interactions. The group participates in wildlife surveys (birds, bats, butterflies, etc.), BioBlitzes, nature photography workshops, and other outdoor activities. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1598970079841-CBQAM8V0H1DFQCUQZM6J/teenbanding-1024x683.jpg Education Activities - Teen Bird Camp Scholarships BCAS offers full scholarships to two summer ornithology camps for Boulder County area students: Hog Island Maine Birding Camp and American Birding Association Camp Colorado Birding Camp. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1615997015300-0V5FALJZJ5C7Y7HPOSLH/PrarieDog-300x205.png Education Activities - eMovement Initiative [Something about the program] https://www.kevinks.com/ecosystem-stewardship daily 0.75 2021-03-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617062653334-OE3CS8RT5B76AEFV0WM8/BrownCreeper.jpg Ecosystem Stewardship Brown Creeper https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617062727231-HAMEPPZ2WVAS2IL5OYNQ/WhitethroatedSwift.jpg Ecosystem Stewardship White-throated Swift https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617062653334-OE3CS8RT5B76AEFV0WM8/BrownCreeper.jpg Ecosystem Stewardship Brown Creeper https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617062727231-HAMEPPZ2WVAS2IL5OYNQ/WhitethroatedSwift.jpg Ecosystem Stewardship White-throated Swift https://www.kevinks.com/carbon-offset daily 0.75 2021-03-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617063023718-86Y0ZMZN1RLRIIXQVUYV/carbon-offset-logo-300x300.jpeg Carbon Offset https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1617063023718-86Y0ZMZN1RLRIIXQVUYV/carbon-offset-logo-300x300.jpeg Carbon Offset https://www.kevinks.com/new-page-1 daily 0.75 2022-12-27 https://www.kevinks.com/productscvdfilms daily 0.75 2024-08-31 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1699029450795-XNYUQJ0GJYSZPICKFKLR/TestBannerText1.jpg Seeding for CVD Films https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/0eeccc40-be06-4101-b9ae-951a4db5c736/cvd-substrates.jpeg Seeding for CVD Films - Make it stand out Various substrates seeded using detonation nanodiamond suspensions: a silicon wafer (2D substrate), a field tip array (3D), and nanodiamond coated carbon nanotubes. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/56308f63-a54d-4a17-bcaf-7b22cb5fb3cf/blueseed-size.jpeg Seeding for CVD Films - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/d87eaac5-7c7a-4aa5-a52a-db5fb244f5aa/opalseed-size.jpeg Seeding for CVD Films - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/359a5e99-d0d2-4758-b5c2-f26da0c841f0/greyseed-size.jpeg Seeding for CVD Films - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/3e7371d4-3ae9-4bc7-a82d-a25bd2fc3739/MSDS-icon.jpeg Seeding for CVD Films - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/7ed72ad4-71b5-469c-9867-e21d2848f4d0/Technical-Info-icon-1.jpeg Seeding for CVD Films - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/0eeccc40-be06-4101-b9ae-951a4db5c736/cvd-substrates.jpeg https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/56308f63-a54d-4a17-bcaf-7b22cb5fb3cf/blueseed-size.jpeg https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/d87eaac5-7c7a-4aa5-a52a-db5fb244f5aa/opalseed-size.jpeg https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/359a5e99-d0d2-4758-b5c2-f26da0c841f0/greyseed-size.jpeg https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/3e7371d4-3ae9-4bc7-a82d-a25bd2fc3739/MSDS-icon.jpeg https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/7ed72ad4-71b5-469c-9867-e21d2848f4d0/Technical-Info-icon-1.jpeg https://www.kevinks.com/swallows daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772428540-ELN0OZGRMIIS2OXMKB1A/HornedLark.jpg Lark and Swallows - Horned Lark (Copy) Horned Lark - Status: Fairly common year-round resident on the plains; common summer resident in the Alpine tundra. - Populations: Possibly the most abundant breeding bird in Colorado, Horned Larks nest in close-cropped shortgrass prairies on the plains and in similar environments in the Alpine tundra. They breed across Europe, Asia, northern Africa, and in North America from the Alaskan tundra south to the Andes. - Conservation: Horned Larks remain the most abundant species on many Colorado Breeding Bird Survey routes, though survey data do indicate a moderate decline across North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772439934-DV8NY13C3XNLA5PFZXKA/TreeSwallow.jpg Lark and Swallows - Tree Swallow (Copy) Tree Swallow - Status: Common summer resident from the plains to the high mountains. - Populations: These acrobatic swallows typically nest in tree cavities in open forests near water. Locally, they nest from the plains to the high mountains, with nests especially abundant in aspen groves. They carefully line their cavity-nests with feathers, and studies indicate that young birds thrive in well-feathered nests. - Conservation: Tree Swallows nest across North America from northern Canada south to Georgia, Arkansas, and south-central California. North American populations appear to have increased in recent years, and their breeding range has expanded into the southeastern United States and formerly treeless areas on the Great Plains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772450507-CG9SNR8TBSG44NF5750Z/VioletGreenSwallow.jpg Lark and Swallows - Violet-green Swallow (Copy) Violet-green Swallow - Status: Common summer resident from the plains to the high mountains. - Populations: Nesting in similar sites to those occupied by Tree Swallows, Violet-green Swallows appear to be more abundant in the foothills and in cliffy areas, where they nest in cliff crevices. However, nesting pairs are most abundant in aspen groves. - Conservation: Considered the second most common breeding swallow in Colorado after Cliff Swallow, Violet-green Swallows breed in western North America, from Alaska to Mexico. Cutting of dead trees and invasion of urban area nesting sites by house sparrows and European starlings may restrict populations in some areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772463087-94UD9ZC4UTT9PTSIZNDJ/NorthernRoughWingedSwallow.jpg Lark and Swallows - Northern Rough-winged Swallow (Copy) Northern Rough-winged Swallow - Status: Fairly common summer resident on the plains and in the foothills. - Populations: These drab but swift-flying swallows typically nest in dirt embankments near streams or gravel ponds. Pairs tend to nest separately, rather than in colonies. - Conservation: Northern Rough-winged Swallows breed throughout the United States and southern Canada south through Central America. They typically arrive in Colorado in March or April. Their breeding range has expanded in the eastern United States in recent years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772477892-K8QI6VHL0EFT0NOCUMRZ/BankSwallow.jpg Lark and Swallows - Bank Swallow (Copy) Bank Swallow - Status: Uncommon summer resident on the plains. - Populations: These colonial, bank-nesting swallows breed in just a few locations in Boulder County, including a gravel pile at Walden Ponds Wildlife Area. They dig their own burrows, then build a nest of dry vegetation and feathers at the end of the burrow. - Conservation: These swallows breed nearly worldwide, but only scattered populations nest in Colorado, mostly on the plains and in the western valleys. While they may benefit from sand and gravel operations, the shifting nature of these operations and destruction of natural embankments may limit their nesting success. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772488507-J8SXOTOQRDT5NA4PT4EY/CliffSwallow.jpg Lark and Swallows - Cliff Swallow (Copy) Cliff Swallow - Status: Very common summer resident, plains to middle elevations. - Populations: Our most abundant swallows, Cliff Swallows nest by the hundreds in colonies under bridges, in culverts, and under overhanging cliffs, primarily on the plains and in the foothills. Their beautifully constructed gourd-shaped mud nests make colonies easy to find, even during winter. - Conservation: Breeding Bird Survey trends indicate a continent-wide increase in nesting populations during recent decades. These suburban-adapted swallows may benefit from construction of bridges and culverts, though humans frequently destroy their nests when they're located on buildings. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592772499734-U3NT49GMYRPGQFKUU2AB/BarnSwallow.jpg Lark and Swallows - Barn Swallow (Copy) Barn Swallow - Status: Very common summer resident on the plains and in mountain communities. - Populations: Aptly-named barn swallows frequently nest inside or under the eaves of barns and other outbuildings, though before European conquest, they nested primarily in caves and on cliffs. Less colonial than Cliff Swallows, they spread out across the landscape, nesting in virtually all human-occupied areas of Colorado. - Conservation: Considered the most widespread of all swallows, Barn Swallows nest in North America, Europe, Africa, and Asia. Colorado breeders winter from Panama south to Argentina and Chile. North American populations appear to be increasing as these urban-adaptive swallows take advantage of human structures and proliferation of deciduous trees in and around human settlements. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/bitterns-herons-and-ibis daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588994504540-5HTIP6NH70NSRSDEM1L1/image-asset.jpeg Bitterns, Herons and Ibis - American Bittern (Copy) American Bittern (Boulder County isolated or restricted) - Status: Uncommon summer resident. Nesting has been documented at a dozen wetland locations on the plains of Boulder County. - Populations: American Bitterns nest in cattail marshes at Boulder Reservoir, Coot Lake, Boulder Valley Ranch, Sawhill and Walden Ponds, White Rocks, and South Boulder Creek State Natural Area. Their ground nests are preyed upon by coyotes, raccoons, and bullsnakes. Males are easily identified by their eerie "oonk-a-loonk" calls, reminiscent of the sound of a hand-operated water pump. - Conservation: Disturbance of marshes throughout Colorado led to this species being listed as high-priority special concern by the Colorado Natural Heritage Program. North American Breeding Bird Survey routes show a 0.6% per year decline throughout North America from 1966-2011. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588994925565-Y82XP1BKIT4MD17TGFL7/image-asset.jpeg Bitterns, Herons and Ibis - Great Blue Heron (Copy) Great Blue Heron - Status: Common summer resident and fairly common winter resident, primarily on the plains. - Populations: Throughout the 20th and early 21st centuries, Great Blue Herons nested in one large heronry in Boulder County, first at Crane Hollow, then at Sawhill Ponds, and finally along Boulder Creek east of 95th Street. This latter heronry, the largest in Colorado, was abandoned recently after most of the cottonwoods used for nesting died. New heronries have sprung up at Crane Hollow, Hygiene, Walden Ponds, and Boulder Reservoir. - Conservation: This highly-adaptive generalist appears to be thriving throughout its North American breeding range, which extends from Baja California north to Alaska and Nova Scotia. The North American Breeding Bird Survey documented a 1.2% per year increase in U.S. numbers from 1966-2011. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995095982-YONZQ1SW9CEN5AOVQHEQ/image-asset.jpeg Bitterns, Herons and Ibis - Great Egret (Copy) Great Egret (Boulder County Rare and Isolated) - Status: Fairly common summer resident. Nests just east of Boulder County in a large heronry at Saint Vrain State Park. - Populations: These large white herons fish throughout the summer on the shores of Union Reservoir, Boulder Reservoir, and Walden Ponds. They nest with other herons in cottonwood groves. They were reported nesting in only two Colorado locations during the first Colorado Breeding Bird Atlas project. - Conservation: North American Breeding Bird Survey data indicates a 2.5% per year increase in numbers from 1966-2011. Here in Colorado, a couple of new nesting colonies have sprouted up during the past two decades. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995217821-UZFO2JWQS5DQOEQCDN9S/image-asset.jpeg Bitterns, Herons and Ibis - Snowy Egret (Copy) Snowy Egret (Boulder County Rare and Isolated) - Status: Fairly common summer resident. Nests just east of Boulder County in a large heronry at Saint Vrain State Park. - Populations: These large white herons fish throughout the summer on the shores of Union Reservoir, Boulder Reservoir, and Walden Ponds. They nest with other herons in cottonwood groves. They were reported nesting in only two Colorado locations during the first Colorado Breeding Bird Atlas project. - Conservation: North American Breeding Bird Survey data indicates a 2.5% per year increase in numbers from 1966-2011. Here in Colorado, a couple of new nesting colonies have sprouted up during the past two decades. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995325189-6OCFCU9KLVFGGE8LPA0H/image-asset.jpeg Bitterns, Herons and Ibis - Green Heron (Copy) Green Heron - Status: Boulder County Isolated. Uncommon to rare summer resident. Nesting has not been reported recently in Boulder County. - Populations: Green Herons breed in a variety of wetland types, including shorelines of rivers, lakes, and reservoirs, as well as freshwater marshes and swamps. Nesting has been reported at a half dozen wetland locations at the base of the Front Range foothills, including two locations in West Denver. - Conservation: Highest North American nesting concentrations occur in mangrove thickets along the southeastern U.S. coast, where dense, tangled vegetation, facilitates nest concealment and defense. Here in more arid Colorado, anecdotal records suggest that numbers have increased slightly since the early 1900s. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588996157734-530E485VH6KMJZ6VXRKN/image-asset.jpeg Bitterns, Herons and Ibis - Black-crowned Night Heron (Copy) Black-crowned Night Heron - Status: Boulder County Isolated. Uncommon to rare summer resident. Nesting has not been reported recently in Boulder County. - Populations: Green Herons breed in a variety of wetland types, including shorelines of rivers, lakes, and reservoirs, as well as freshwater marshes and swamps. Nesting has been reported at a half dozen wetland locations at the base of the Front Range foothills, including two locations in West Denver. - Conservation: Highest North American nesting concentrations occur in mangrove thickets along the southeastern U.S. coast, where dense, tangled vegetation, facilitates nest concealment and defense. Here in more arid Colorado, anecdotal records suggest that numbers have increased slightly since the early 1900s. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995583637-3S1NMPG0PRD21IQXFB0B/image-asset.jpeg Bitterns, Herons and Ibis - White-faced Ibis (Copy) White-faced Ibis - Status: Fairly common spring migrant. Uncommon to rare summer resident and fall migrant. Nesting has not been documented in Boulder County. - Populations: These long-beaked, exotic-appearing herons nest in freshwater marshes in scattered areas of Colorado, primarily in the San Luis Valley and on the Western Slope. Flocks of 50-100 frequent Boulder County marshes and shorelines in May, especially around Boulder Reservoir and Sawhill and Walden Ponds. - Conservation: Since nesting Ibis are extremely sensitive to rising and falling water levels, breeding numbers fluctuate dramatically from year to year. In the San Luis Valley, where as many as 500 pairs have nested during some years, nest productivity is constrained by overgrazing, human disturbance, and predation by corvids and raccoons. Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588995641061-CHOC136I5LXEBHPVZAEW/image-asset.jpeg Bitterns, Herons and Ibis - White-faced Ibis (winter) (Copy) White-faced Ibis (winter) - Status: Fairly common spring migrant. Uncommon to rare summer resident and fall migrant. Nesting has not been documented in Boulder County. - Populations: These long-beaked, exotic-appearing herons nest in freshwater marshes in scattered areas of Colorado, primarily in the San Luis Valley and on the Western Slope. Flocks of 50-100 frequent Boulder County marshes and shorelines in May, especially around Boulder Reservoir and Sawhill and Walden Ponds. - Conservation: Since nesting Ibis are extremely sensitive to rising and falling water levels, breeding numbers fluctuate dramatically from year to year. In the San Luis Valley, where as many as 500 pairs have nested during some years, nest productivity is constrained by overgrazing, human disturbance, and predation by corvids and raccoons. Photo © 2014, Gerhard Assenmacher https://www.kevinks.com/starling-pipit-and-waxwings daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224659729-3YEWBPDDAD7AJQ718HNB/EuropeanStarling.jpg Starling, Pipit and Waxwings - European Starling (Copy) European Starling - Status: Very common year-round resident, especially in and around towns; plains to high mountain communities. - Populations: Ubiquitous wherever human habitations occur but less common in more natural areas, such as the Boulder Mountain Park and Indian Peaks Wilderness. First introduced from Europe into North America during the 19th century and now probably our most common bird, preying on songbird nests and displacing cavity-nesting birds. - Conservation: Breeds in North America from Alaska to northern Mexico and Florida. Populations stable or increasing throughout most of North American breeding range, though numbers have declined in Great Britain. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224677407-KNT98QN4CK43K2UJYBOT/AmericanPipit.jpg Starling, Pipit and Waxwings - American Pipit (Copy) American Pipit - Status: Fairly common summer resident on the tundra; fairly common to uncommon migrant on the plains. - Populations: These sparrow-sized songbirds with shorebird-like habits nest on the alpine tundra from New Mexico north to Alaska, Baffin Island, and Greenland. Often seen during migration on wetter areas of the plains, they typically arrive in the tundra in April and some stay into October. - Conservation: Nesting populations appear to be stable, though few data are available. Ski area construction and other disturbances in the alpine tundra have fragmented nesting habitat in Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224697597-QP4UDN7EKI9UCWP3DIU8/BohemianWaxwing.jpg Starling, Pipit and Waxwings - Bohemian Waxwing (Copy) Bohemian Waxwing - Status: Irregular winter resident, plains to mid-elevation mountains. - Populations: A winter visitor to Boulder County, abundant during some years and not present during others. During years with above-average fall/winter fruit crops, flocks of hundreds will descend on junipers and mountain-ash trees, forming berry brigades to pass fruits from one beak to another. They nest exclusively in western Canada and Alaska. - Conservation: Because of the remoteness of their nesting areas in northern boreal forests, little is known about population trends. Here in Boulder County, urban planting of mountain-ashes and other trees that bear fruit deep into winter has probably attracted wandering flocks. Photo © 2013, Mike Milicia https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593224707807-7Z0H9A5UA4XGJS25LQ3D/CedarWaxwing.jpg Starling, Pipit and Waxwings - Cedar Waxwing (Copy) Cedar Waxwing - Status: Uncommon summer resident on the plains; fairly common to uncommon year-round resident, plains and foothills. - Populations: These beautiful and somewhat secretive waxwings nest in late summer in deciduous woodlands of the plains and lower foothills. Look for them along Coal Creek, South Boulder Creek, St. Vrain Creek, and other streams cutting down through the hills and at Sawhill and Walden Ponds. During some years, large flocks may overwinter. - Conservation: Populations appear secure throughout most breeding areas in the northern United States and southern and central Canada, with increases reported on the western plains, where the spread of deciduous trees has increased foraging and nesting opportunities. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/owls daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162809161-Z96BKJENYUR14OD3FJ52/BarnOwl.jpg Owls - Barn Owl (Copy) Barn Owl - Status: Uncommon summer resident; rare winter resident. - Populations: Barn owls were first documented nesting in Boulder County in 1943, when a cliff nest was found at White Rocks, along Boulder Creek. They now nest in tree cavities, cliffs, barns, silos, and other human structures throughout the plains. - Conservation: While populations have declined in areas of the Great Plains as dead trees and old barns have been removed and rodent populations reduced by use of pesticides, numbers have increased steadily in Boulder County during the last several decades. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162820379-ITLMTC3VA2K6R0Y75C1B/FlammulatedOwl.jpg Owls - Flammulated Owl (Copy) Flammulated Owl - Status: Uncommon summer resident. - Populations: These tiny, reclusive owls nest in woodpecker holes in aspen groves or mature ponderosa pine woodlands from 6000-10,000 feet. Listen for their surprisingly forceful hooting calls as they advertise nesting territories in late spring. - Conservation: Little is known about Flammulated Owl population trends in North America. In Boulder County they appear to thrive in old-growth ponderosa pine woodlands and mature aspen groves, both of which have been reduced by subdivision development, catastrophic fires, and insect infestations. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162828623-LPG3XTD8SU3F48OP38SY/EasternScreechOwl.jpg Owls - Eastern Screech Owl (Copy) Eastern Screech Owl - Status: Uncommon year-round resident. - Populations: Boulder County Nature Association studies suggest that about one pair per linear mile nests along St. Vrain Creek and Boulder Creek on the plains. Pairs also nest in city parks in Boulder, Louisville, Longmont, and other communities--wherever there are tree cavities and sufficient prey populations. - Conservation: Little is known about eastern screech-owl population trends in Colorado. Populations appear to be stable or slightly increasing in Boulder County as density of deciduous woodlands on the plains and in towns increases. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162837487-U2Y06CN1ADNG7ED283GB/GreatHornedOwl.jpg Owls - Great Horned Owl (Copy) Great Horned Owl - Status: Fairly common year-round resident. - Populations: These human-adapted habitat generalists nest throughout Boulder County, from towns on the plains to subalpine forests. They usually use abandoned hawk nests, but may also lay their eggs in tree cavities and broken-topped snags. - Conservation: Great horned owl populations have exploded in Boulder County, threatening nesting populations of prey species that include long-eared owl and burrowing owl. The number observed on Boulder Christmas Bird Counts increased from 1 in 1950 to more than 100 in 2013. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162848580-ZMA24V9K32BOJ1X3YU8Y/NorthernPygmyOwl.jpg Owls - Northern Pygmy Owl (Copy) Northern Pygmy Owl - Status: Fairly common year-round resident. - Populations: These human-adapted habitat generalists nest throughout Boulder County, from towns on the plains to subalpine forests. They usually use abandoned hawk nests, but may also lay their eggs in tree cavities and broken-topped snags. - Conservation: Great horned owl populations have exploded in Boulder County, threatening nesting populations of prey species that include long-eared owl and burrowing owl. The number observed on Boulder Christmas Bird Counts increased from 1 in 1950 to more than 100 in 2013. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592163597618-UPWLOOY3F5J8JU195UYW/BurrowingOwl.jpg Owls - Burrowing Owl (Copy) Burrowing Owl - Status: Uncommon summer resident. - Populations: Pairs arrive in prairie dog colonies on the plains in April, laying their eggs in abandoned prairie dog burrows by mid-May. They often line nest burrows with dung, which they apparently used to attract beetles and other insect prey. Nests can fledge anywhere from 1 to 10 young. - Conservation: Once considered abundant in Boulder County, burrowing owls now nest in only a few scattered locations, and nest productivity appears to be too low to maintain stable populations. Fragmentation of prairie dog colony nesting habitat, along with mortality from automobile collisions and predation by urban-adapted predators, appear to be the greatest threats to their survival locally. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162872388-VFXWPITYBIZ58TUOBTH1/LongEaredOwl.jpg Owls - Long-eared Owl (Copy) Long-eared Owl - Status: Uncommon to rare year-round resident. - Populations: Considered fairly common in Boulder County plains and foothills woodlands during the late 19th century, long-eared owls are now difficult to find, with only a half dozen nesting locations documented during the past two decades. Predation by larger and more suburban-adapted great horned owls may pose the greatest threat to their survival. - Conservation: Imperiled in Boulder County, possibly due to competition with and predation by larger great horned owls. Listed as threatened or endangered in a half dozen states. However, due to their secrecy and nomadism, little is known about long-term North American population trends. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162880893-9H7IRWPXTBAC8VROFIPF/ShortEaredOwl.jpg Owls - Short-eared Owl (Copy) Short-eared Owl - Status: Rare winter resident. - Populations: One or two short-eared owls tend to appear in wetlands west of Boulder Reservoir and west of Lagerman Reservoir each winter. Look for them swooping low over cattail marshes around dusk or dawn. There is just one nesting record for Boulder County, from the late 19th century. - Conservation: Despite widespread concern over their decline in specific areas, listed as "secure" by the Nature Conservancy. Has always been considered rare in Boulder County, though numbers of observations appear to have declined during recent years. Loss of wetlands surrounded by natural grasslands is a primary concern. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162891046-7HJPZRARWM0K305UJM26/NorthernSawWhetOwl.jpg Owls - Northern Saw-whet Owl (Copy) Northern Saw-whet Owl - Status: Rare winter resident. - Populations: One or two short-eared owls tend to appear in wetlands west of Boulder Reservoir and west of Lagerman Reservoir each winter. Look for them swooping low over cattail marshes around dusk or dawn. There is just one nesting record for Boulder County, from the late 19th century. - Conservation: Despite widespread concern over their decline in specific areas, listed as "secure" by the Nature Conservancy. Has always been considered rare in Boulder County, though numbers of observations appear to have declined during recent years. Loss of wetlands surrounded by natural grasslands is a primary concern. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162901216-20E1PPP4OQ8JVEH8C9TK/BorealOwl.jpg Owls - Boreal Owl (Copy) Boreal Owl - Status: Uncommon year-round resident. - Populations: Boreal owls nest almost exclusively in the boreal, or subalpine life zone. They were first detected in Boulder County in 1984, when their haunting, winnowing calls were heard near Brainard Lake and west of Eldora. Breeding studies indicate there is little or no overlap between their nesting habitat and that of the closely related northern saw-whet owl. - Conservation: Due to the difficulty of surveying breeding habitat in the high mountains during the late winter and spring calling and nesting period, little is known about boreal owl populations in Boulder County and throughout Colorado. Photo © 2013, Don Whittaker https://www.kevinks.com/thrushes daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776457962-SLVIJRZYRBV2NTEUOGHZ/EasternBluebirdMale.jpg Thrushes - Eastern Bluebird (m) (Copy) Eastern Bluebird (m) - Status: Uncommon migrant; rare summer resident in the foothills and on the plains. - Populations: Populations: While Eastern Bluebirds are occasionally reported on the Boulder Christmas Bird Count, only two Boulder County nesting sites have been documented recently, both at the base of the foothills. Relative newcomers to Colorado, these cavity-nesters have followed the spread of deciduous woodlands and orchards westward across the western plains. - Conservation: North American bluebird populations plummeted throughout the first two-thirds of the 20th century as introduced European Starlings and House Sparrows appropriated nest sites. Pesticide use on farms and removal of dead trees also harmed nesting populations. Conservation efforts, combined with creation of thousands of bluebird nest box trails throughout the continent, have contributed to a more than doubling of nesting populations during the past 50 years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776467574-7R6H0BFOVQCHD37VKIWF/EasternBluebirdFemale.jpg Thrushes - Eastern Bluebird (f) (Copy) Eastern Bluebird (f) - Status: Uncommon migrant; rare summer resident in the foothills and on the plains. - Populations: Populations: While Eastern Bluebirds are occasionally reported on the Boulder Christmas Bird Count, only two Boulder County nesting sites have been documented recently, both at the base of the foothills. Relative newcomers to Colorado, these cavity-nesters have followed the spread of deciduous woodlands and orchards westward across the western plains. - Conservation: North American bluebird populations plummeted throughout the first two-thirds of the 20th century as introduced European Starlings and House Sparrows appropriated nest sites. Pesticide use on farms and removal of dead trees also harmed nesting populations. Conservation efforts, combined with creation of thousands of bluebird nest box trails throughout the continent, have contributed to a more than doubling of nesting populations during the past 50 years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776480724-OV6JTRE070P7991JLVYN/WesternBluebirdMale.jpg Thrushes - Western Bluebird (m) (Copy) Western Bluebird (m) - Status: Fairly common summer resident in the foothills; rare winter resident. - Populations: These beautiful cavity-nesters favor open ponderosa pine woodlands throughout the western half of the state. In Boulder County several hundred pairs nest in bluebird boxes at Walker Ranch, Betasso Preserve, and other foothills parks, where they frequently supplant nesting Mountain Bluebirds. Bluebirds sally forth from perches to snatch insects from the air. - Conservation: Listed as "rare and declining" in Boulder County as late as 1990, Western Bluebirds have made a spectacular recovery. However, they remain dependent on artificial nest boxes, especially as forestry practices still include mass cutting of dead snags. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776491920-B4CX5O01VUIM3FUGLQHN/WesternBluebirdFemale.jpg Thrushes - Western Bluebird (f) (Copy) Western Bluebird (f) - Status: Fairly common summer resident in the foothills; rare winter resident. - Populations: These beautiful cavity-nesters favor open ponderosa pine woodlands throughout the western half of the state. In Boulder County several hundred pairs nest in bluebird boxes at Walker Ranch, Betasso Preserve, and other foothills parks, where they frequently supplant nesting Mountain Bluebirds. Bluebirds sally forth from perches to snatch insects from the air. - Conservation: Listed as "rare and declining" in Boulder County as late as 1990, Western Bluebirds have made a spectacular recovery. However, they remain dependent on artificial nest boxes, especially as forestry practices still include mass cutting of dead snags. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776501228-TN80VQO3X6WVRZ2QJWUL/MountainBluebirdMale.jpg Thrushes - Mountain Bluebird (m) (Copy) Mountain Bluebird (m) - Status: Fairly common summer resident and migrant; uncommon winter resident. - Populations: These habitat generalists nest in piñon-juniper woodlands, ponderosa pine woodlands, spruce-fir forests, aspen groves, riparian woodlands, and rural residential areas throughout the western two-thirds of the state. In addition to woodpecker holes and artificial nest boxes, they nest on cabin ledges and in holes in building walls, abandoned Cliff Swallow nests, cattle chutes, ski lift towers, and basketball standards. - Conservation: North American populations have rebounded during the past few decades as bluebird trails were created and forestry practices evolved toward retaining more dead trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776510761-TIXOQSC9WANWGZKGP9SF/MountainBluebirdFemale.jpg Thrushes - Mountain Bluebird (f) (Copy) Mountain Bluebird (f) - Status: Fairly common summer resident and migrant; uncommon winter resident. - Populations: These habitat generalists nest in piñon-juniper woodlands, ponderosa pine woodlands, spruce-fir forests, aspen groves, riparian woodlands, and rural residential areas throughout the western two-thirds of the state. In addition to woodpecker holes and artificial nest boxes, they nest on cabin ledges and in holes in building walls, abandoned Cliff Swallow nests, cattle chutes, ski lift towers, and basketball standards. - Conservation: North American populations have rebounded during the past few decades as bluebird trails were created and forestry practices evolved toward retaining more dead trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776519444-S23CABBG6T99CA6VRIHB/TownsendsSolitaire.jpg Thrushes - Townsend's Solitaire (Copy) Townsend's Solitaire - Status: Common year-round resident in foothills and mountains. - Populations: Most easily located by their upward-spiraling song, Swainson's thrushes breed throughout the mountains of Colorado, primarily in willow thickets and aspen groves, but also in open conifer forests containing shrubbery. They build their nests in thick vegetation close to the ground. Migrants can be heard singing on the plains of Boulder County well into June. - Conservation: Townsend's Solitaires nest throughout the western half of Colorado, and their North American breeding range includes mountain ranges from Alaska to New Mexico. Little is known about nesting population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776535489-L08X5SEBO5NAW23OFCMF/SwainsonsThrush.jpg Thrushes - Swainson's Thrush (Copy) Swainson's Thrush - Status: Fairly common summer resident in mountain willow carrs. - Populations: Most easily located by their upward-spiraling song, Swainson's thrushes breed throughout the mountains of Colorado, primarily in willow thickets and aspen groves, but also in open conifer forests containing shrubbery. They build their nests in thick vegetation close to the ground. Migrants can be heard singing on the plains of Boulder County well into June. - Conservation: Among our most commonly observed migrants during late spring, Swainson's Thrushes breed throughout forested regions of Canada, Alaska, New England, and the western states. Due to the remoteness of most nesting locations, little is known about population trends. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776545468-8IJJK61EV8GSPLZ8KKDW/HermitThrush.jpg Thrushes - Hermit Thrush (Copy) Hermit Thrush - Status: Fairly common summer resident in mountain conifer forests. - Populations: The ethereal, flute-like songs of these reclusive thrushes haunt conifer forests from the foothills to the high mountains. Pairs generally place their nest in a shrub or on a tree trunk close to the ground, and they feed their young a diet of insects, spiders, earthworms, sow bugs, snails, and wild currants. - Conservation: Found primarily in open forests in the East and closed-canopy conifer forests in the West, Hermit Thrushes breed from Newfoundland to central Alaska and south to the Great Lakes area, New Mexico, and California. Clear-cutting of conifer forests has decimated nesting populations in parts of the West. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776555680-N4ONOQWI0EI3W9130YZ6/AmericanRobin.jpg Thrushes - American Robin (Copy) American Robin - Status: Abundant year-round resident from the plains to the high mountains. - Populations: These adaptive omnivores nest from the plains to the high subalpine and thrive around human settlements, where they feast on earthworms, insects, and wild and domestic fruits. Poisoning of robins by DDT that accumulated on tree leaves and was then ingested by earthworms was reported by Rachel Carson and contributed to our awareness of the toxicity of this lethal pesticide. - Conservation: Robins thrive throughout Colorado and most of North America, and their populations are probably increasing in urban areas and along prairie streams, where deciduous trees provide nesting sites and lawns and meadows provide foraging areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776564922-G571KJS3W3HIWR00Y9BI/GrayCatbird.jpg Thrushes - Gray Catbird (Copy) Gray Catbird - Status: Fairly common summer resident in foothills shrublands and plains riparian woodlands. - Populations: Catbirds typically nest in dense foliage near the ground, so in Boulder County they're most often found in foothills shrublands and in shrubby areas along prairie streams. They sing their scratchy, complex songs from prominent perches overlooking nesting areas. - Conservation: Numbers have increased in areas of the foothills as shrub vegetation has proliferated after cattle were removed from open space properties. On the plains, shrub vegetation is just not dense enough in most places, even along streams, to facilitate nesting. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776574451-2LYYIO69GTPC7J8ZHW7N/NorthernMockingbird.jpg Thrushes - Northern Mockingbird (Copy) Northern Mockingbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776585235-3TYY9OKYOAQUXM1GSXLJ/SageThrasher.jpg Thrushes - Sage Thrasher (Copy) Sage Thrasher - Status: Uncommon to rare resident and migrant in in shrub thickets in the foothills and on the plains. - Populations: Their affinity for shrublands makes these conspicuous singers fairly common in sagebrush areas of northwestern Colorado, the western valleys, and the San Luis Valley but rare in Boulder County. Look for them, especially during spring migration and late summer, at Rabbit Mountain and Doudy Draw. - Conservation: Breeding Bird Survey data suggest that numbers of nesting pairs have increased dramatically in Colorado, perhaps as a result of improved grazing practices in sagebrush uplands. In Boulder County, breeding Sage Thrashers have all but disappeared, with only a couple of nesting observations reported during the past two decades. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592776595768-RQC81H70TU9ZDA2VLM3T/BrownThrasher.jpg Thrushes - Brown Thrasher (Copy) Brown Thrasher - Status: Rare summer resident in plains riparian woodlands. - Populations: Among our most talented mimic thrushes, Brown Thrashers can sing hundreds of distinct phrases from conspicuous perches in deciduous woodlands and shelterbelts on the plains. A decidedly eastern species, they just make it into Boulder County, where pairs have been observed nesting at Rabbit Mountain and south of Eldorado Springs. - Conservation: Breeding throughout the eastern United States and southern Canada, Brown Thrashers have gradually extended their nesting range westward as deciduous woodlands and shrublands developed along prairie streams and in rural shelterbelts. However, Breeding Bird Survey data show a substantial drop in North American populations during the last three decades of the 20th century. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/loons-and-grebes daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889290070-8J3SSKIM11T7EB4B7VMH/image-asset.jpeg Loons and Grebes - Common Loon (Copy) Common Loon - Status: Uncommon to rare spring and fall migrant on the plains, usually at large reservoirs. - Populations: A few migrating Common Loons are observed each fall and spring on Valmont Reservoir, Baseline Reservoir, Boulder Reservoir, or other large bodies of water on the plains. They nest from Montana and the Great Lakes northward to Alaska and Baffin Island. - Conservation: Birds of North America described North American breeding populations as "robust," with approximately a quarter of a million nesting pairs. However, breeding pairs are regionally threatened by fluctuating water levels in reservoirs, nest disturbance by recreational users, chemicals, and possibly, global warming. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889366047-BMPZUK43NRO0FNHHKR4P/image-asset.jpeg Loons and Grebes - Pied-billed Grebe (Copy) Pied-billed Grebe - Status: Fairly common summer resident in wetlands on the plains. Uncommon to fairly common year-round reservoir on the plains. - Populations: Though often seen and heard on the plains during the summer breeding season, nesting is rarely documented in Boulder County. Likely nesting locations include Sawhill and Walden ponds wildlife areas and South Boulder Creek State Natural Area. Male’s booming voice, a rhythmic series of gulping and cooing notes, may reveal nesting territories. - Conservation: North American nesting populations appear to be fairly stable, though disturbance of wetlands in some regions has led to significant declines in numbers of successful nests. In Colorado Pied-Billed Grebes became much more common during the twentieth century as reservoirs were constructed and marshlands created. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889464028-92LP0PU61MA0EKTFBDW7/image-asset.jpeg Loons and Grebes - Horned Grebe (Copy) Horned Grebe - Status: Fairly common migrant on the plains during spring and fall. Breeds from northern plains to Alaska and Hudson's Bay. - Populations: Small to large flocks are observed regularly in spring and fall on Baseline Reservoir, Valmont Reservoir, Union Reservoir, Boulder Reservoir, Sombrero Marsh, and at Coot Lake. Best distinguished from Eared Grebe by bill and head shape, along with details of head patterns. - Conservation: Though one of the most abundant breeding grebes in North America, its breeding range appears to be contracting to the northwest, and biologists are not sure why. Potential threats include pesticides, degradation of marsh nesting habitat, and mortality from fishing nets. Photo © 2014, PHOTOGRAPHER https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889556408-IL3GKI6CVRXOXFK06OB9/image-asset.jpeg Loons and Grebes - Horned Grebe (breeding) (Copy) Horned Grebe (breeding) - Status: Fairly common migrant on the plains during spring and fall. Breeds from northern plains to Alaska and Hudson's Bay. - Populations: Small to large flocks are observed regularly in spring and fall on Baseline Reservoir, Valmont Reservoir, Union Reservoir, Boulder Reservoir, Sombrero Marsh, and at Coot Lake. Best distinguished from Eared Grebe by bill and head shape, along with details of head patterns. - Conservation: Though one of the most abundant breeding grebes in North America, its breeding range appears to be contracting to the northwest, and biologists are not sure why. Potential threats include pesticides, degradation of marsh nesting habitat, and mortality from fishing nets. Photo © 2014, PHOTOGRAPHER https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889610116-MS2BGL6DQTTB43I9D8V9/image-asset.jpeg Loons and Grebes - Eared Grebe (Copy) Eared Grebe (Boulder County rare and declining nesting populations) - Status: Uncommon to fairly common spring and fall migrant on ponds and reservoirs throughout the plains. Nesting was documented in Boulder County prior to 1900, and pairs have nested recently at Union Reservoir, just east of Boulder County. - Populations: Small flocks appear in April and May, and again throughout the fall, at Coot Lake, Boulder Reservoir, Baseline Reservoir, and other large bodies of water on the plains. Pairs build floating nests in shallow water from the Texas Panhandle north to the prairie pothole region of southern Canada. - Conservation: Eared Grebes were heavily hunted for their soft feathers, which were used in the millinery trade, and their pickled eggs were sold throughout North America during the early 20th century. Populations have since rebounded and appear to be fairly stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592144128761-O2LV80X4OA2H4J083JVE/EaredGrebeWinter.jpg Loons and Grebes - Eared Grebe (winter) (Copy) Eared Grebe (winter) (Boulder County rare and declining nesting populations) - Status: Uncommon to fairly common spring and fall migrant on ponds and reservoirs throughout the plains. Nesting was documented in Boulder County prior to 1900, and pairs have nested recently at Union Reservoir, just east of Boulder County. - Populations: Small flocks appear in April and May, and again throughout the fall, at Coot Lake, Boulder Reservoir, Baseline Reservoir, and other large bodies of water on the plains. Pairs build floating nests in shallow water from the Texas Panhandle north to the prairie pothole region of southern Canada. - Conservation: Eared Grebes were heavily hunted for their soft feathers, which were used in the millinery trade, and their pickled eggs were sold throughout North America during the early 20th century. Populations have since rebounded and appear to be fairly stable. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889816160-BVV33OU9LML84A2YTIUG/image-asset.jpeg Loons and Grebes - Western Grebe (Copy) Western Grebe - Status: Fairly common to common migrant and summer resident on large reservoirs on the plains. Nesting has not been documented in Boulder County. - Populations: Flocks of several hundred Western Grebes may appear on our larger reservoirs during spring and fall migration. Nesting has been documented in neighboring Weld County and throughout much of northern Colorado, and in May these large and attractive grebes perform their spectacular, "running on water," courtship displays on local reservoirs. Up to 100 pairs have nested at Eleven Mile Reservoir in South Park, where they lay their eggs in floating nests located far from shore. - Conservation: This species has become much more common in Colorado with the construction of reservoirs to irrigate farmlands, but fluctuating water levels in reservoirs makes nesting a risky proposition. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889894118-7LNAJAQ7TTHL902BHQ0K/image-asset.jpeg Loons and Grebes - Clark's Grebe (Copy) Clark's Grebe - Status: Fairly common to common migrant and summer resident on large reservoirs on the plains. Nesting has not been documented in Boulder County. - Populations: Flocks of several hundred Western Grebes may appear on our larger reservoirs during spring and fall migration. Nesting has been documented in neighboring Weld County and throughout much of northern Colorado, and in May these large and attractive grebes perform their spectacular, "running on water," courtship displays on local reservoirs. Up to 100 pairs have nested at Eleven Mile Reservoir in South Park, where they lay their eggs in floating nests located far from shore. - Conservation: This species has become much more common in Colorado with the construction of reservoirs to irrigate farmlands, but fluctuating water levels in reservoirs makes nesting a risky proposition. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588889966224-4WZFR7MO5C1MQKK1SQSI/image-asset.jpeg Loons and Grebes - Double-crested Cormorant (Copy) Double-crested Cormorant - Status: Fairly common year-round resident, with highest numbers usually reported during summer. - Populations: Double-crested Cormorants nest in heronries in eastern Boulder County and overwinter at Valmont Reservoir. Numbers have increased dramatically in recent years, partially due to existence of open water throughout the winter and possibly due to proliferation of heronries throughout Boulder County. - Conservation: Local protection of breeding sites, the 1972 ban on DDT, and continuing construction of reservoirs has contributed to increasing populations throughout their extensive breeding range, which extends from Alaska and Baja California westward across the western deserts, central plains, and Great Lakes to Newfoundland and Florida. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588890181659-3FAOP4XLLQ84HS895IRL/image-asset.jpeg Loons and Grebes - American White Pelican (Copy) American White Pelican - Status: Fairly common to common migrant and summer resident. Nesting has not been documented in Boulder County. - Populations: American White Pelicans nest at three known locations in Colorado--Riverside Reservoir East of Greeley, Antero Reservoir in South Park, and McFarlane Reservoir in North Park--and only three dozen locations in all of North America. The largest colony, at Chase Lake in North Dakota, has supported tens of thousands of breeding pairs. Adults may fly 30 miles or more away from nesting colonies to fish. - Conservation: American White Pelican populations increased dramatically after DDT was banned in 1972. North American Breeding Bird Survey data indicate an increase of about 2.5% per year from 1981-2011. Varying water levels in reservoirs, along with predation by carnivores, result in dramatic variations in breeding colony sizes. Photo © 2020, Kevin Smith https://www.kevinks.com/woodpeckers daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181367585-R61XTL5T2WUJ5A6LIWHV/WilliamsonsSapsuckerMale.jpg Woodpeckers - Williamson's Sapsucker (male) (Copy) Williamson's Sapsucker (male) - Status: Fairly common resident of mountain conifer forests. - Populations: Listen for the Morse code-like rapping of these gregarious woodpeckers in mid- to high-elevation forests. Males excavate nest cavities in aspens or sometimes conifers. - Conservation: Breeding from southeastern British Columbia to central Arizona and New Mexico, these sapsuckers thrive in ponderosa pine forest and aspen groves. Their numbers increase during outbreaks of insect infestations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181377762-RETWJWPPVPV79ZN0T4PJ/WilliamsonsSapsuckerFemale.jpg Woodpeckers - Williamson's Sapsucker (female) (Copy) Williamson's Sapsucker (female) - Status: Fairly common resident of mountain conifer forests. - Populations: Listen for the Morse code-like rapping of these gregarious woodpeckers in mid- to high-elevation forests. Males excavate nest cavities in aspens or sometimes conifers. - Conservation: Breeding from southeastern British Columbia to central Arizona and New Mexico, these sapsuckers thrive in ponderosa pine forest and aspen groves. Their numbers increase during outbreaks of insect infestations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181752960-AGRBZZ4AKGKG82T4XMKX/RedNapedSapsucker.jpg Woodpeckers - Red-naped Sapsucker (Copy) Red-naped Sapsucker - Status: Fairly common resident in mountain aspen groves. - Populations: These small sapsuckers typically forage in deciduous woodlands and excavate their nest cavities in dead or dying aspens. The noisy chatter of young sapsuckers makes these nests relatively easy to find. In Boulder County they range from about 6000-10,500 feet. - Conservation: Forestry practices that eliminate dead or dying trees may limit nesting populations, but these sapsuckers still appear to be thriving throughout the mountains of Colorado. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181403394-4EX7NFLK8QINH0NJIK50/DownyWoodpecker.jpg Woodpeckers - Downy Woodpecker (Copy) Downy Woodpecker - Status: Fairly common resident in mountain aspen groves. - Populations: These small sapsuckers typically forage in deciduous woodlands and excavate their nest cavities in dead or dying aspens. The noisy chatter of young sapsuckers makes these nests relatively easy to find. In Boulder County they range from about 6000-10,500 feet. - Conservation: Forestry practices that eliminate dead or dying trees may limit nesting populations, but these sapsuckers still appear to be thriving throughout the mountains of Colorado. Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181430932-EEYKY05GTO3GDKGHNUN5/HairyWoodpecker.jpg Woodpeckers - Hairy Woodpecker (Copy) Hairy Woodpecker - Status: Common year-round resident, primarily foothills and mountains. - Populations: Hairy Woodpeckers excavate nest cavities primarily in conifers from plains communities to high-elevation mountain forests. Their "peeek" calls are slightly lower pitched and their bills longer than those of the smaller downy woodpeckers. - Conservation: These generalists have continued to thrive throughout central and western Colorado despite forestry activities that limit the availability of potential nesting trees. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181441945-M3WB8K90SGFCO7SVEBZH/ThreeToedWoodpecker.jpg Woodpeckers - Three-toed Woodpecker (Copy) Three-toed Woodpecker - Status: Uncommon year-resident of mountain forests, most abundant in recently-burned areas. - Populations: In years following a fire, these small woodpeckers forage on wood-borers that chew on the fire-killed trees. They excavate their nest cavities in dead or dying conifers from 7000-12,000 feet. - Conservation: These mountain-dwelling woodpeckers nest in boreal forests from Scandinavia, Northern Europe, and Asia to North America, primarily in areas with widely-dispersed human populations. However, fire-suppression in conifer forests has probably reduced foraging and nesting opportunities. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592181451571-PXG5TD8KPQ1FN2PHJUVO/NorthernFlicker.jpg Woodpeckers - Northern Flicker (Copy) Northern Flicker - Status: Very common year-around resident throughout Boulder County. - Populations: These urban-adapted generalists excavate nest cavities in cottonwoods, aspens, conifers, fence posts, utility poles, or the siding of human dwellings from the plains to the high mountains. They feast on grasshoppers, crickets, caterpillars, and various other insect larvae. - Conservation: Northern Flickers appear to be thriving throughout Boulder County and throughout most of North America. Competition with European Starlings may limit populations in some areas. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/pheasants-grouse daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773187012-9LY7J3QA9X96HQ07QTE0/image-asset.jpeg Pheasants, Grouse - Ring-necked Pheasant (m) (Copy) Ring-necked Pheasant (m) - Status: Uncommon year-round resident. - Populations: Pheasants have been introduced periodically to our area by game clubs, and their numbers rise and fall depending on the severity of our winters. Recent reports have come from rural areas east of Boulder, around Louisville, and east and south of Longmont. - Conservation: Pheasants were introduced to North America from Eurasia and have proliferated in rural areas, especially in the eastern half of the continent. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773657754-VVKE6DXMQJ695GMNW6B7/image-asset.jpeg Pheasants, Grouse - White-tailed Ptarmigan (summer plumage) (Copy) White-tailed Ptarmigan (summer plumage) - Status: Uncommon year-round resident in the alpine tundra and krumholz region, generally above 11,000 feet. - Populations: North America's southernmost ptarmigan species nests from New Mexico north to southeastern Alaska. Physical adaptations, including feathered feet and eyelids, enable them to survive alpine winters. Look for them in the Indian Peaks Wilderness above tree line in summer and at the interface between the upper forest and the alpine tundra in winter. - Conservation: Global warming will eventually shrink the area of white-tailed ptarmigan habitat, forcing the birds northward. Road and ski area construction in the high mountains probably limits and fragments nesting habitat. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588773761186-TQ9VLD0DE7DO58BI0SVN/image-asset.jpeg Pheasants, Grouse - White-tailed Ptarmigan (winter plumage) (Copy) White-tailed Ptarmigan (winter plumage) - Status: Uncommon year-round resident in the alpine tundra and krumholz region, generally above 11,000 feet. - Populations: North America's southernmost ptarmigan species nests from New Mexico north to southeastern Alaska. Physical adaptations, including feathered feet and eyelids, enable them to survive alpine winters. Look for them in the Indian Peaks Wilderness above tree line in summer and at the interface between the upper forest and the alpine tundra in winter. - Conservation: Global warming will eventually shrink the area of white-tailed ptarmigan habitat, forcing the birds northward. Road and ski area construction in the high mountains probably limits and fragments nesting habitat. Photo © 2013, Scott Rashid https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588816045733-DJX7BQOPML1HND8G0VVO/image-asset.jpeg Pheasants, Grouse - Dusky Grouse (Copy) Dusky Grouse - Status: Uncommon year-round resident. - Populations: These secretive grouse inhabit Boulder County conifer forests from 6000-11,500 feet. In spring you can hear the males "drumming" with their wings (a soft, hollow-sounding series of hoots) from the Boulder Mountain Park to the Indian Peaks Wilderness. Females lay their eggs on the ground, and young fledge shortly after hatching. - Conservation: Recreational pressures in the foothills appear to be pushing dusky grouse farther up into the mountains. Roaming dogs and feral cats, along with urban-adapted predators such as coyote and raccoon, may predate nests. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588816128260-26PMQZDEXLANPQETNIKD/image-asset.jpeg Pheasants, Grouse - Wild Turkey (Copy) Wild Turkey - Status: Fairly common year-round resident in the foothills; uncommon year-round resident on the plains. - Populations: Flocks of wild turkeys roam through ponderosa pine woodlands in the lower foothills throughout the year. Look for them at Heil Ranch, Hall Ranch, Walker Ranch, and on the flanks of Eldorado Mountain. Turkeys also skulk through shrubby areas adjacent to prairie streams, including North Saint Vrain Creek and Boulder Creek. - Conservation: Largely as a result of reintroduction programs initiated during the 1960s, the North American wild turkey population has ballooned to more than 7 million. Turkeys now commonly strut down side streets of many prairie towns. Populations in Boulder County have increased dramatically during the past two decades. It's not known whether Wild Turkeys are native to Boulder County. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/columbidae daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162135394-BAO4MO7PPVL05VY6JL3L/RockDove.jpg Pigeons and Doves - Rock Pigeon (Dove) (Copy) Rock Pigeon (Dove) - Status: Abundant year-round resident. - Populations: Rock Doves, commonly known as Pigeons, which were introduced to North America from Europe, nest on cliffs, buildings, and other structures throughout Boulder County from the plains to mountain communities. - Conservation: Efforts to poison pigeons in parts of North America have not led to dramatic declines in their numbers. They continue to thrive wherever humans are present. Photo © 2013, Alan Grant https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162145170-I5V6S4ZKLK7873ZV0YMN/MourningDove.jpg Pigeons and Doves - Mourning Dove (Copy) Mourning Dove - Status: Common summer resident; uncommon winter resident. - Populations: These urban-adapted, habitat generalists nest in shrubby environments throughout the plains, foothills, and low mountains of Boulder County. - Conservation: One of the most abundant birds in North America with an estimated population of 300-500 million individuals. Populations appear to have declined in areas invaded by Eurasian Collared-Doves and in agricultural areas where shrubbery and woodlots have been removed. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592162155815-YNQJTZFPWSVT8JBGQ2VY/EurasianCollaredDove.jpg Pigeons and Doves - Eurasian Collared Dove (Copy) Eurasian Collared Dove - Status: Fairly common year-round resident. - Populations: Eurasian collared-doves first appeared in Boulder County around 2000 and now thrive on the plains and in the low foothills. Native to the Indian subcontinent, they were distributed around the world through the caged bird trade and now inhabit most of North America, from Florida to Alaska. - Conservation: Populations have exploded across North America during the past two decades. It's still not known how much they compete with or displace native mourning doves. Photo © 2013, Evan Assenmacher https://www.kevinks.com/nighthawks daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180196478-93KXZ942KGDYBM97RIUL/CommonNighthawk.jpg Nighthawks, - Common Nighthawk (Copy) Common Nighthawk - Status: Fairly common summer resident. - Populations: Nests on the ground from the plains to the upper montane, predominantly in shortgrass prairie and ponderosa pine woodlands. Listen for the fart-like "vroorror" as males dive over their nesting territories and the wind rushes through their feathers. - Conservation: Fragmentation of native grasslands by crops and towns, along with suburbanization of areas at the base of the Front Range foothills, have contributed to apparent declines in Colorado nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180206988-5A65KS4WH6TUWJJO7QD6/CommonPoorwill.jpg Nighthawks, - Common Poorwill (Copy) Common Poorwill - Status: Fairly common summer resident. - Populations: Nests on the ground from the plains to the upper montane, predominantly in shortgrass prairie and ponderosa pine woodlands. Listen for the fart-like "vroorror" as males dive over their nesting territories and the wind rushes through their feathers. - Conservation: Fragmentation of native grasslands by crops and towns, along with suburbanization of areas at the base of the Front Range foothills, have contributed to apparent declines in Colorado nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180216354-I5WKO16FPMWUUN9LV3NC/ChimneySwift.jpg Nighthawks, - Chimney Swift (Copy) Chimney Swift - Status: Uncommon summer resident. - Populations: First discovered nesting in Boulder County in chimneys of the University of Colorado's Mackey Auditorium, these urban-adapted swifts have slowly spread up and down the Front Range. However, they are rarely seen except when entering or leaving nesting chimneys. - Conservation: Not surprisingly, these urban-adapted swifts appear to have expanded throughout Eastern Colorado as human settlements have proliferated. However, Breeding Bird Survey data suggest that North American populations are declining. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180227787-JLPMBMDYDSZI35TL4IX8/WhitethroatedSwift.jpg Nighthawks, - White-throated Swift (Copy) White-throated Swift - Status: Uncommon summer resident. - Populations: First discovered nesting in Boulder County in chimneys of the University of Colorado's Mackey Auditorium, these urban-adapted swifts have slowly spread up and down the Front Range. However, they are rarely seen except when entering or leaving nesting chimneys. - Conservation: Not surprisingly, these urban-adapted swifts appear to have expanded throughout Eastern Colorado as human settlements have proliferated. However, Breeding Bird Survey data suggest that North American populations are declining. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180254518-CBU5XGKKJDO6XRWTITMJ/BroadTailedHummingbird.jpg Nighthawks, - Broad-tailed Hummingbird (Copy) Broad-tailed Hummingbird - Status: Common summer resident. - Populations: Nesting from the low foothills to the high mountains, broad-tails are conspicuous because of the distinctive trilling sound that the male makes with his wings while patrolling nesting territories. They like wet areas, especially aspen groves and streamside woodlands. - Conservation: Their adaptability to hummingbird feeders and to humans in general has no doubt enabled broad-tails to expand their nesting populations in some areas. They breed all the way from northern Wyoming south to Guatemala. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180466882-X0HSK614YHNBM8HOLMD0/RufousHummingbird.jpg Nighthawks, - Rufous Hummingbird (Copy) Rufous Hummingbird - Status: Fairly common summer migrant. - Populations: These beautiful and feisty hummingbirds nest from northern California and northwestern Wyoming all the way up to Alaska and Yukon Territory. In spring they migrate north through California's Central Valley, where nectar-laden wildflowers are already blooming; in late summer they migrate south through wildflower meadows of the Central Rockies. - Conservation: Breeding Bird Survey data show significant declines in British Columbia, Washington, and Oregon. Forestry activities may affect nesting success, but the estimated world population nevertheless stands at a fairly robust 6.5 million. Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592180482549-TZ3VGGMKJVCYUKDP3C09/BeltedKingfisher.jpg Nighthawks, - Belted Kingfisher (Copy) Belted Kingfisher - Status: STATUS - Populations: Belted Kingfishers nest throughout much of North America, laying their eggs in burrows in a steep earthen bank0, usually close to water. They eat mainly small fish. Listen for their chattering calls as they zoom over streams and gravel ponds on the plains. - Conservation: North American populations appeared to decline by approximately 50% from 1974-94. However, populations appear stable or are increasing in Boulder County. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/scolopacidae daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159101595-FRJ8YG6XVTN0QC4S0X9B/Killdeer.jpg Shorebirds - Killdeer (Copy) Killdeer - Status: Very common summer resident; uncommon winter resident. - Populations: This shorebird conceals its speckled eggs on bare ground and has adapted readily to gravel parking lots, construction sites, and agricultural fields. Look for Killdeers on the plains wherever there is bare or disturbed ground near wetlands or bodies of water. - Conservation: Literally considered the least endangered bird in Colorado on the Colorado Priorities 1995 list, since it seems to thrive in human-disturbed environments. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159111956-CQAEQBMC5WHIKPXECILJ/BlackNeckedStilt.jpg Shorebirds - Black-necked Stilt (Copy) Black-necked Stilt - Status: Rare migrant. - Populations: These elegant shorebirds nest in scattered locations of eastern and central Colorado, with the largest numbers occurring in the San Luis Valley. In Boulder County, look for them in April and May foraging in shallow water and mud flats around our prairie reservoirs and ponds. Several pairs have nested at Lower Latham Reservoir, in Weld County. - Conservation: Fewer than 500 pairs nest in Colorado. Throughout North America, Breeding Bird Survey results suggest a statistically significant increase in numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159153092-A6NKJYK12BH2JLVUVRW4/AmericanAvocet.jpg Shorebirds - American Avocet (Copy) American Avocet - Status: STATUS - Populations: Look for migrating and a few nesting avocets in shallow, often brackish water on the plains, where they sweep their upcurved bills like pendulums through the brine. Pairs nest in loose colonies, placing their flimsy nests in simple scrapes on mud flats. - Conservation: Colorado nesting range appears to have gradually expanded since the late 19th century, with the largest concentrations occurring in the San Luis Valley. North American Breeding Bird Survey data indicate a modest decline in overall numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159163383-0XX7A5KI2ROJZRDWKPLD/AmericanAvocetWinter.jpg Shorebirds - American Avocet (winter) (Copy) American Avocet (winter) - Status: STATUS - Populations: Look for migrating and a few nesting avocets in shallow, often brackish water on the plains, where they sweep their upcurved bills like pendulums through the brine. Pairs nest in loose colonies, placing their flimsy nests in simple scrapes on mud flats. - Conservation: Colorado nesting range appears to have gradually expanded since the late 19th century, with the largest concentrations occurring in the San Luis Valley. North American Breeding Bird Survey data indicate a modest decline in overall numbers from 1966-2011. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159173017-MUK9UBF8LQ2N2ERY78Q7/SemipalmatedSandpiper.jpg Shorebirds - Semipalmated Sandpiper (Copy) Semipalmated Sandpiper - Status: Uncommon migrant. - Populations: These drab little sandpipers frequent mud flats on the plains in April-May and August-September. They nest on the Arctic Plain, from Alaska to Baffin Island. - Conservation: Construction of reservoirs on the plains of Boulder County has probably expanded migratory habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159189898-3PH1H83UMR4OENHI74W6/SemipalmatedPlover.jpg Shorebirds - Semipalmated Plover (Copy) Semipalmated Plover - Status: Uncommon spring migrant . - Populations: These striking sandpipers frequent mud flats of prairie ponds and reservoirs during April and May. They nest far to the north, in Alaska and northern Canada. - Conservation: Construction of reservoirs on the plains of Boulder County has probably expanded migratory habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159201178-AMPKPPJAGQDMYOWKDW5W/SpottedSandpiper.jpg Shorebirds - Spotted Sandpiper (Copy) Spotted Sandpiper - Status: Fairly common summer resident; uncommon migrant. - Populations: Spotted Sandpipers nest around prairie ponds and reservoirs, including Boulder Reservoir, Coot Lake, Sawhill Ponds, and Union Reservoir. Look for their "teetering" displays and listen for their clear, whistled flight calls. - Conservation: This widespread shorebird nests from the northern edge of the taiga in Alaska and Canada south to California and North Carolina. Colorado and North American populations appear secure--probably because they are able to nest in a wide variety of sites, including clumps of grass, among streamside rocks, under logs, and on ledges. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159209859-LJRKHI0B5QQ78OE50GHE/SolitarySandpiper.jpg Shorebirds - Solitary Sandpiper (Copy) Solitary Sandpiper - Status: Fairly common spring migrant; uncommon to rare fall migrant. - Populations: Look for these striking, medium-sized sandpipers during spring and late summer migration at Sawhill Ponds, Union Reservoir, Gayner Lakes, and Baseline Reservoir. They nest from Alaska east across central Canada to Newfoundland. - Conservation: North American Breeding Bird Survey data suggest a nonsignificant decline in numbers from 1966-2011. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159219049-3I0AZ0ITVROVA4QDDG3F/GreaterYellowlegs.jpg Shorebirds - Greater Yellowlegs (Copy) Greater Yellowlegs - Status: Fairly common spring and fall migrant. - Populations: Dozens migrate through Boulder County from March-April and July-October. Some may linger into December. They nest from Alaska east across Canada to Newfoundland. - Conservation: North American Breeding Bird Survey data indicate a nonsignificant increase in numbers from 1966-2011. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159230185-YJ4FYQ9ZHX0GHRPI3KEE/LesserYellowlegs.jpg Shorebirds - Lesser Yellowlegs (Copy) Lesser Yellowlegs - Status: Fairly common spring and fall migrant. - Populations: More abundant than Greater Yellowlegs, these long-legged shorebirds are hard to miss in April and May at Union Reservoir or Walden Ponds. They pass through Boulder County on their way south from August-October after nesting in Alaska and northern Canada. - Conservation: Populations remain fairly secure, since nesting habitat is in areas sparsely inhabited by humans. However, North American Breeding Bird Survey data indicate a nonsignificant decline in numbers from 1966-2011. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159241715-2RGKX0AWVX9I1LR6OPN5/MarbledGodwit.jpg Shorebirds - Marbled Godwit (Copy) Marbled Godwit - Status: Uncommon spring and fall migrant. - Populations: Fairly common on lakes and ponds in eastern Boulder County in April as they pass through on their way north to nesting areas in the prairie pothole region of the northern United States and south-central Canada. - Conservation: Breeding Bird Survey data indicate no significant increases or decreases since 1966, but historic breeding areas have been lost in Minnesota, Wisconsin, Iowa, and Nebraska since the early 20th century. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159252709-TH49VKRDU5A0FWH93JJC/BairdsSandpiper.jpg Shorebirds - Baird's Sandpiper (Copy) Baird's Sandpiper - Status: Uncommon to fairly common spring and fall migrant. - Populations: One of our most common sandpipers when flocks pass through in August and September, returning from nesting areas on the Arctic slope. Uncommon in May. - Conservation: Both breeding and wintering populations appear secure globally. Most of the moss tundra and low shrub tundra habitat where they nest remains intact. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159266296-IDTXDRMUBSTA74YUK7B2/WesternSandpiper.jpg Shorebirds - Western Sandpiper (Copy) Western Sandpiper - Status: Uncommon spring and fall migrant. - Populations: Look for them mixed in with flocks of other sandpipers at Boulder Reservoir, Walden Ponds, Baseline Reservoir, McIntosh Lake, and Union Reservoir in April-May and again in August-September. They nest in northern and western Alaska. - Conservation: Total population of about 3.5 million birds nests and winters in brackish tidal flats that receive minimal disturbance from humans. Drainage and conversion of wetlands at migration stopover points and wintering areas is probably the biggest threat to their populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159278618-A8DJ1ID94G1IX0C5S90E/WilsonsSnipe.jpg Shorebirds - Wilson's Snipe (Copy) Wilson's Snipe - Status: Fairly common to uncommon year-round resident. - Populations: Wilson's Snipes range all the way from the plains to the high mountains, where they nest in shallow marshes. Listen for the warbling, winnowing sound made by the wind rushing through the male's tail feathers as he display-dives over his nesting territory, April-June. - Conservation: This habitat generalist numbers more than 5 million in North America, but populations have contracted in areas hit by drought or where marshes have been converted to farmland or human settlements. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159289558-I996B9FB3G55TX7D5LHP/WilsonsPhalarope.jpg Shorebirds - Wilson's Phalarope (Copy) Wilson's Phalarope - Status: Fairly common migrant; uncommon summer resident. - Populations: Fairly common in shallow lakes and marshes on the plains in May and June, and a few pairs may nest successfully in Boulder County. We lie near the southern edge of their breeding range, which extends from northern New Mexico and Nevada northward to Yukon Territory, Saskatchewan, and Minnesota. - Conservation: Because of their dependence on shallow, ephemeral lakes and ponds, populations fluctuate wildly depending on the amount of rainfall. Nesting populations in the northern Great Plains have been hard hit by drought in recent years. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592159302880-O8G3AJZX6KJGNLID93E5/RedNeckedPhalarope.jpg Shorebirds - Red-necked Phalarope (Copy) Red-necked Phalarope - Status: Rare spring and fall migrant. - Populations: Red Phalaropes nest in tundra ponds along the Arctic Plain, and a few pass through Boulder County from year-to-year. This holarctic species nests from extreme northern Canada west through northern Russia and to Iceland. - Conservation: World population stands at around 5 million, though remoteness of nesting sites makes these shorebirds difficult to count. Northern Canada population show signs of declining. Likely vulnerable to oil spills and other disturbance of Arctic nesting habitat. Photo © 2014, Gerhard Assenmacher https://www.kevinks.com/laridae daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161188524-6KONE0IQUV3EB9JIZ62L/BonapartesGull.jpg Gulls and Terns - Bonaparte's Gull (Copy) Bonaparte's Gull - Status: Uncommon spring and fall migrant. - Populations: Look for these small, acrobatic gulls sprinkled in with flocks of Franklin's gulls on the plains in spring and migrating separately in October and November. They nest from southern Canada northward to Alaska. - Conservation: Breeding colonies lie in remote areas where there is minimal human disturbance, and little is known about population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161200400-M53469BJBUFXZ21HMMY8/FranklinsGull.jpg Gulls and Terns - Franklin's Gull (Copy) Franklin's Gull - Status: Fairly common spring, late summer, and fall migrant. - Populations: Flocks of several thousand pass through eastern Boulder County in late summer. Look for them especially at Union Reservoir and Boulder Reservoir, where they congregate on mud flats. They nest from northern Colorado north to Canada's Northwest Territories. - Conservation: The North American population stands at around one mullion, and little is known about population trends or conservation status, since most pairs breed in remote, large marshes that are difficult to census. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161209975-3Q1ZNFOZLNBU27WLEVRF/MewGull.jpg Gulls and Terns - Mew Gull (Copy) Mew Gull - Status: Rare winter resident. - Populations: This medium-sized, locally rare gull is difficult to distinguish from the locally common Ring-billed Gull. Note the smaller bill, shorter legs, and dark iris. Mew Gulls nest from north-central Canada west to the Aleutian Islands. - Conservation: Due to the remoteness of their nesting areas, little is known about population trends and conservation needs, but the total global population is estimated at more than one million nesting pairs. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161222222-95RXTBRV28FTZHGR9QPG/RingBilledGull.jpg Gulls and Terns - Ring-billed Gull (Copy) Ring-billed Gull - Status: Abundant winter resident and fairly common spring and fall migrant. Uncommon in summer. - Populations: Flocks of these medium-sized gulls gather on most lakes and ponds in Boulder County throughout the winter, and quite a few nonbreeding juveniles and adults stay for the summer months. Though ring-bills have nested in the San Luis Valley, their principal breeding range extends from Oregon, Wyoming, the Great Lakes, and Pennsylvania north to Northwest Territories and Labrador. - Conservation: World population stands at around 2.5 million, and dietary flexibility may protect this generalist from alterations to nesting and wintering habitat. Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161234367-AADRMQ733EQBTPSJEPJN/CaliforniaGull.jpg Gulls and Terns - California Gull (Copy) California Gull - Status: Fairly common spring and late summer migrant. Uncommon summer and winter resident. - Populations: California Gulls nest on sandy islands at Elevenmile Reservoir, in South Park; Riverside Reservoir east of Greeley; Adobe Creek Reservoir in North Park; and John Martin Reservoir in the Arkansas River valley. Their North American breeding range extends from California's Central Valley, the Great Salt Lake basin, and Colorado north to British Columbia and Northwest Territories. - Conservation: North American breeding populations appear to of the increased since the 1930s, and in Colorado, this colonial-nester has begun to breed on islands in large reservoirs. Since these aggressive gulls prey on nests of other ground-nesting birds, these new nesting colonies may threaten nesting populations of threatened least terns and piping plovers. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161285963-GFKHSJXCY648AWX6KU0E/HerringGull.jpg Gulls and Terns - Herring Gull (Copy) Herring Gull - Status: Fairly common winter resident and fall migrant. - Populations: Herring Gulls mix in with flocks of Ring-billed Gulls on Boulder County lakes from October-March. Note their larger size and distinctively pink legs. They nest from British Columbia, the Great Lakes area, and South Carolina north to Alaska and Labrador. - Conservation: U.S. breeding population has increased from around 8000 nesting pairs in 1900 to more than 100,000 nesting pairs in 1990. Larger numbers breed in Canada. Herring gulls thrive around human coastal communities, and humans have controlled nesting populations to protect other ground-nesting birds. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161297228-ZD3563Q2OYZ5NZ15AONE/ThayersGull.jpg Gulls and Terns - Thayer's Gull (Copy) Thayer's Gull - Status: Uncommon winter resident. - Populations: Distinguishable from Herring Gulls only by their darker iris and dark-streaked outer primary feathers, these large gulls gather with flocks of other gulls on Boulder County lakes and ponds throughout the winter. They nest in extreme northern Canada. - Conservation: Breeds in small, isolated colonies and is much less numerous than similar-appearing Herring Gull. Like other gulls, has benefited from construction of large landfills and reservoirs in wintering areas. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161311190-37G6WTJMNY3QCHEPXQY5/LesserBlackBackedGull.jpg Gulls and Terns - Lesser Black-backed Gull (Copy) Lesser Black-backed Gull - Status: Rare summer resident. - Populations: As you are scanning flocks of winter gulls with a scope or binoculars, look for individuals with darker wings. Lesser black-backs nest primarily in Europe. - Conservation: Persecuted populations were decimated during the 19th century and have slowly recovered since then, but this species remains threatened throughout much of its European breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161322772-CFCYAGUUA28JTQFUHNTY/BlackTern.jpg Gulls and Terns - Black Tern (Copy) Black Tern - Status: Uncommon spring and late summer migrant. Nests just east and north of Boulder County. - Populations: These acrobatic terns swoop over prairie reservoirs in late spring and late summer, and a few pairs nest in Eastern Colorado. Nesting pairs are fairly common in the Nebraska Sandhills and northward into the prairie pothole region of the Dakotas and southern Canada. - Conservation: North American Breeding Bird Survey data indicated an average annual decline of 3.1% from 1966-96, with the greatest decline occurring within the prairie region. Loss or degradation of wetlands where black terns nest or overwinter remains a major concern. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592161332932-G9SJ97G9G80FHA8732CF/ForstersTern.jpg Gulls and Terns - Forster's Tern (Copy) Forster's Tern - Status: Uncommon spring and late summer migrant. Nests just east and north of Boulder County. - Populations: These acrobatic terns swoop over prairie reservoirs in late spring and late summer, and a few pairs nest in Eastern Colorado. Nesting pairs are fairly common in the Nebraska Sandhills and northward into the prairie pothole region of the Dakotas and southern Canada. - Conservation: North American Breeding Bird Survey data indicated an average annual decline of 3.1% from 1966-96, with the greatest decline occurring within the prairie region. Loss or degradation of wetlands where black terns nest or overwinter remains a major concern. Photo © 2013, Matthew Studebaker https://www.kevinks.com/towhees-and-sparrows daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593228989245-KBXGEX9TB9O45PWI09DY/GreenTailedTowhee.jpg Towhees and Sparrows - Green-tailed Towhee (Copy) Green-tailed Towhee - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229001589-M6HLVUABN8THOUVZVRCK/SpottedTowhee.jpg Towhees and Sparrows - Spotted Towhee (Copy) Spotted Towhee - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229014917-13VIBBEC05Z6T7JZCQHE/AmericanTreeSparrow.jpg Towhees and Sparrows - American Tree Sparrow (Copy) American Tree Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229027425-AVHHO60KIMKG3RRIIRH3/ChippingSparrow.jpg Towhees and Sparrows - Chipping Sparrow (Copy) Chipping Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229042660-XN49WH0CB0GITTSXA8W9/BrewersSparrow.jpg Towhees and Sparrows - Brewer's Sparrow (Copy) Brewer's Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229055350-NPBPAPCLIQN7GW3P9228/VesperSparrow.jpg Towhees and Sparrows - Vesper Sparrow (Copy) Vesper Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229065901-OOZBPVMZGG8NFPKB9ZNY/LarkSparrow.jpg Towhees and Sparrows - Lark Sparrow (Copy) Lark Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229076379-BGVI7KKPG47K99FWEUVH/LarkBunting.jpg Towhees and Sparrows - Lark Bunting (Copy) Lark Bunting - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229086265-AWTHTKV4NZYRRASZL3FD/SavannahSparrow.jpg Towhees and Sparrows - Savannah Sparrow (Copy) Savannah Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229097475-CDMJW85731KYVTF4NSZ4/GrasshopperSparrow.jpg Towhees and Sparrows - Grasshopper Sparrow (Copy) Grasshopper Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229113680-AOOONVQPHOIKKLVTDC1K/FoxSparrow.jpg Towhees and Sparrows - Fox Sparrow (Copy) Fox Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229126748-220E7A9GCT3P0STNYRRI/SongSparrow.jpg Towhees and Sparrows - Song Sparrow (Copy) Song Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229140104-VHVH5HVNN3INSRPZDMDJ/LincolnSparrow.jpg Towhees and Sparrows - Lincoln's Sparrow (Copy) Lincoln's Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229150274-D6MO84C96DXUEBTAGMPF/WhiteCrownedSparrow.jpg Towhees and Sparrows - White-crowned Sparrow (Copy) White-crowned Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593229161680-GPK5NTS031Z5EDDMR2LQ/DarkEyedJunco.jpg Towhees and Sparrows - Dark-eyed Junco (Copy) Dark-eyed Junco - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/rallidae daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158186770-PJNQ7D4E9S9BFB3CI6YI/VirginiaRail.jpg Rails, Coot and Crane - Virginia Rail (Copy) Virginia Rail - Status: Uncommon year-round resident. - Populations: These secretive rails nest in cattail marshes from the plains of Boulder County up into the montane parklands. They are best identified by their harsh, "ki-dik, ki-dik, ki-dik," calls, given throughout the spring and summer on nesting territories. Listen for them at Sawhill Ponds and in the wetlands west of Boulder Reservoir. - Conservation: Numbers have diminished in areas where farmlands have replaced freshwater marshes. North American Breeding Bird Survey results indicate a steady decline in populations from 1966-2011. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158198547-ZZN3ZCI6J9409KCDHOYX/Sora.jpg Rails, Coot and Crane - Sora (Copy) Sora - Status: Uncommon summer resident. - Populations: Soras nest in a variety of wetlands, especially cattail marshes on the plains. Listen for their descending "whump- whump- whump- whump- whump- whump-sploosh" calls at Sawhill Ponds and in the wetlands west of Boulder Reservoir, as well as in montane wetlands. - Conservation: This is the most abundant and widely distributed rail in North America, and little if any range contraction has been noted. However, due to the secretive nature of Soras, little is known about their population status. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158207878-X5UFA2ZFJ0U4BS0E6UTK/AmericanCoot.jpg Rails, Coot and Crane - American Coot (Copy) American Coot - Status: Common year-round resident. - Populations: American Coots nest in a variety of wetlands, preferring marshes with tall emergent vegetation. In Boulder County they nest around reservoirs and in freshwater marshes up to about 8000 feet. - Conservation: Numbers appear to be fairly stable in Colorado and throughout their North American breeding range. Draining of wetlands is always a threat, though these adaptive birds seem to do well in a variety of wetland habitats. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592158226612-AJLQ89QY58NLFJC9VVN2/SandhillCrane.jpg Rails, Coot and Crane - Sandhill Crane (Copy) Sandhill Crane - Status: Uncommon fall migrant; rare spring migrant. - Populations: Sandhill Cranes nest from western Colorado and western Nebraska north to arctic Canada, Alaska, and Siberia. The flocks that fly through Boulder County each October consist mostly of Greater Sandhill Cranes headed for wintering areas in Arizona, New Mexico, and West Texas. - Conservation: Both Greater Sandhill Crane (around 120,000) and Lesser Sandhill Crane (around 600,000) numbers continue to grow, and breeding ranges are slowly expanding. More than half a million Sandhill Cranes gather along the Platte River in Western Nebraska each spring during March-April migration. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/wrens daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777938652-5B9PM4EVFL14PBV5CB56/RockWren.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Rock Wren (Copy) Rock Wren - Status: Fairly common summer resident in rocky areas from the foothills to alpine tundra. - Populations: These vocal, acrobatic wrens nest primarily in rocky areas, from the low foothills all the way up to the tundra. For unknown reasons, they build pebble trails across the rocks to their nests, which are constructed in rock crevices from twigs, grasses, wool, feathers, and plant material. - Conservation: Rock Wrens nest across western North America from southern Canada clear south to Central America. Breeding Bird Survey data indicate steady declines in their populations, especially in eastern Colorado. Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777948301-KDSWDWPL6LA13V8UWFE0/CanyonWren.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Canyon Wren (Copy) Canyon Wren - Status: Fairly common year-round resident in cliffy areas, primarily in the foothills. - Populations: These sweet-singing wrens nest almost exclusively on cliff faces, especially in the foothills. From February through August, their sad, descending songs are hard to miss in canyons of the Boulder Mountain Park. They attach their nests to overhanging ledges or rock faces, sallying forth to glean insects and spiders from the rock. - Conservation: In Colorado Canyon Wrens nest from 3900 feet to 8500 feet, and overall, they breed from the Rocky Mountain foothills to British Columbia and south to Chiapas. Since they nest in locations inaccessible to most humans (except rock climbers), their nesting populations face few threats. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777960820-MRU5LE1GGLREYLX4AIDU/HouseWren.jpg Wrens, Gnatcatcher, Kinglets and Dipper - House Wren (Copy) House Wren - Status: Very common summer resident in shrubby areas from the plains to the mid-mountains. - Populations: These secondary cavity-nesters breed wherever there is dense shrub vegetation, from the plains to around 10,000 feet. A single male constructs multiple stick nests in a tree cavity or building ledge, perhaps hoping to impress a female or to divert the attention of predators from the chosen nest. Their rich, bubbly song, though difficult for beginning birders to categorize, is unmistakable once learned. - Conservation: House Wrens breed throughout North and South America, and they are among the most abundant breeding birds in Colorado. Breeding numbers have increased in Boulder County where cattle have been removed from foothill shrublands and where fires or logging have opened up conifer forests and created more snags for nesting. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777971502-8TUCD4WZ715M4N327UG7/MarshWren.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Marsh Wren (Copy) Marsh Wren - Status: Uncommon year-round resident in marshy areas of the plains. - Populations: Marsh Wrens are new arrivals to Boulder County, having been reported nesting here for the first time during the 2000s. Highly aggressive males attach multiple, globular nests to cattails or other marsh vegetation, and they destroy nearby nests of blackbirds and other Marsh Wrens. They accomplish all this well racing up and down the cattails and singing energetically; in fact, a single male may have a repertoire of more than 100 song phrases. - Conservation: Never common in Colorado, Marsh Wrens may have expanded their nesting range recently as cattail marshes matured around prairie reservoirs and gravel ponds. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777998403-O2A1LRMPUCBKGV9MVT2G/BlueGrayGnatcatcher.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Blue-gray Gnatcatcher (Copy) Blue-gray Gnatcatcher - Status: Fairly common summer resident in shrubby areas and open woodlands of the foothills. - Populations: These perky little insectivores breed in piñon-juniper woodlands throughout southern and western Colorado and in ponderosa pine woodlands along the Front Range foothills. Beginning in April, they construct artful cup nests from grass, moss, feathers, fur, and lichens in the fork of two small branches or sometimes in a saddle of a horizontal limb. - Conservation: Populations have increased and expanded northward in North America during recent decades. Along the Colorado Front Range, increased shrub density as cattle were removed from the foothills may have contributed to this range expansion. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592777983365-VDY9E7RKZB44GP9KNVQM/GoldenCrownedKinglet.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Golden-crowned Kinglet (Copy) Golden-crowned Kinglet - Status: Uncommon to fairly common summer resident of subalpine conifer forests and winter resident of foothills and mountains conifer forests. - Populations: Without being alert to the extremely high-pitched "see-see-see-chick-a-dee song of this tiny insectivore, you're likely to miss it as it hops around in conifer treetops in the subalpine life zone. These kinglets thrive in mature to old-growth Engleman spruce/subalpine fir forests, where they weave hanging nests from bark, lichens, mosses, webs, and fur. - Conservation: Conservation of mature subalpine forests throughout the high country of Boulder County and elsewhere has probably contributed to modest increases in Golden-crowned Kinglet nesting populations in recent decades. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592778018663-VKEE14C0QWTQJSYU5EKW/RubyCrownedKinglet.jpg Wrens, Gnatcatcher, Kinglets and Dipper - Ruby-crowned Kinglet (Copy) Ruby-crowned Kinglet - Status: Common year-round resident, primarily of mountain conifer forests. - Populations: The lilting, complex songs of these acrobatic kinglets fill our mountain conifer forests from May through August. Nests are constructed from mosses, lichens, and other plant material and tucked into crevices in the bark of conifers, making them difficult to locate. - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592778030164-RIVY03VE202TAO3FHLE0/AmericanDipper.jpg Wrens, Gnatcatcher, Kinglets and Dipper - American Dipper (Copy) American Dipper - Status: Fairly common year-round resident of streams from the base of the foothills to the alpine tundra. - Populations: The joyful, complex songs of American Dippers echo off foothill and mountain canyon cliffs throughout the year. Pairs defend nesting territories in summer and lower-elevation foraging territories in winter. They dive into the rushing water, using their wings to shoot through the current as they snatch insect larvae from under rocks. Listen and look for them from White Rocks on the plains to Fourth of July Mine on South Arapaho Peak. - Conservation: American Dippers forage in mountain, coastal, and desert streams from Alaska to Panama. Some breeding pairs have benefited from construction of bridges and nest boxes over and along streams; however, channelization of streams and degradation of streamside embankments have reduced the number of natural nesting sites. Pollution from mines has devastated insect populations in some nesting areas. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/flycatchers daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186880326-FO1ZDZD43P6WCBRJYNQV/OliveSidedFlycatcher.jpg Flycatchers, Shrikes and Vireos - Olive-sided Flycatcher (Copy) Olive-sided Flycatcher - Status: Uncommon summer resident in foothills and lower mountain forests. - Populations: These medium-sized flycatchers, famous for their distinctive "whip-three-beers" song, inhabit ponderosa pine and other open forests from Walker Ranch westward to the low subalpine zone. They also breed in open aspen forests, hiding their nests high in trees among clusters among clusters of horizontal branches. - Conservation: Populations have declined sharply throughout North America in recent decades. Changes in winter habitats and densification of conifer forests in North America may have contributed to this decline. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186891653-JYS4HYPY94S59HDDX5JR/WesternWoodPewee.jpg Flycatchers, Shrikes and Vireos - Western Wood-Pewee (Copy) Western Wood-Pewee - Status: Common summer resident in deciduous and conifer forests from the plains to middle elevations. - Populations: These perky flycatchers nest primarily in riparian woodlands on the plains and ponderosa pine woodlands in the foothills. They place their cup nests 8-80 feet above the ground on a horizontal limb. Most easily recognized by their song, there also are our only common small flycatcher with no distinct eye-ring. - Conservation: These cosmopolitan flycatchers breed throughout western North America, from eastern Alaska to eastern North Dakota, then south to Mexico and Central America. Breeding Bird Survey data suggest a significant decline in continental populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186903716-DD3MJ40CMXW9PDMJ3BML/HammondsFlycatcher.jpg Flycatchers, Shrikes and Vireos - Hammond's Flycatcher (Copy) Hammond's Flycatcher - Status: Fairly common summer resident in conifer forests from the foothills to the high mountains. - Populations: These small flycatchers breed in open conifer forests from 6000-10,000 feet, concealing their nests among conifer needles on horizontal branches. They are virtually identical in appearance and voice to Dusky Flycatchers (though the Dusky's song is somewhat lighter and can be higher-pitched), but Duskys nest mostly in deciduous woodlands. - Conservation: Because of their preference for open and mature conifer forests, populations may be declining in areas where forests have become unnaturally dense. Periodic burning of conifer forests should benefit this flycatcher. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186918828-7I2YAU1I3QZW96SXO7KJ/DuskyFlycatcher.jpg Flycatchers, Shrikes and Vireos - Dusky Flycatcher (Copy) Dusky Flycatcher - Status: Fairly common summer resident in deciduous woodlands, including aspen groves, from the foothills to around 11,000 feet. - Populations: Dusky flycatchers nest in a variety of mostly deciduous habitats, including willows, aspen groves, and open conifer forests. Females build soft, neatly woven nests from grasses and finely shredded plant material and place them in the crotches of shrubs or branches, usually within 15 feet of the ground. - Conservation: These adaptable flycatchers breed from southwestern Yukon, Alberta, and Saskatchewan south throughout most of the mountains of North America. Populations appear to be steady or increasing throughout much of western North America. Photo © 2014, Bill Schmoker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186932636-WMKHX8PH7ZJS6ZEIQRHJ/CordilleranFlycatcher.jpg Flycatchers, Shrikes and Vireos - Cordilleran Flycatcher (Copy) Cordilleran Flycatcher - Status: Fairly common summer resident in aspen groves, willow thickets, and ponderosa pine forests. - Populations: Easily recognized by their high-pitched, rising "bir-dee" song, these active flycatchers place their nests on rock faces, cut banks, barn eaves, and banks of streams in open areas of the forest. - Conservation: Construction of mountain cabins and barns probably has benefited nesting populations in Boulder County. No clear population trends have been identified throughout their breeding habitat, which extends throughout the mountains of North America from southern Alberta south to Oaxaca. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186943054-NN3UYVZQORWHGOZUVSAL/SaysPhoebe.jpg Flycatchers, Shrikes and Vireos - Say's Phoebe (Copy) Say's Phoebe - Status: Fairly common summer resident, primarily on the plains. - Populations: These suburban-adapted flycatchers nest under building eaves, cliff crevices, and in recycled cliff swallow nests from the plains to about 9000 feet. They forage for insects from low perches on rocks, bushes, fence posts, and small trees. - Conservation: Widely distributed throughout low- to middle elevations of Colorado and the Mountain West, Say's Phoebes appear to be holding their own, though urbanization threatens nesting populations in some areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186956876-A4TQS2W41TFY2NCTRQD4/WesternKingbird.jpg Flycatchers, Shrikes and Vireos - Western Kingbird (Copy) Western Kingbird - Status: Fairly common summer resident on the plains. - Populations: Breeding pairs arrive in Colorado and April and begin building their cup nests in cottonwoods and other deciduous trees in May. They may also place their nests on building ledges, telephone poles, fence posts, windmills, stumps, or in tree cavities. - Conservation: Western Kingbirds breed throughout much of western North America, and their populations appear to be stable or increasing. Planting and maturing of deciduous trees along the rivers and around farmhouses on the plains has probably benefited nesting populations. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186971954-46UJPJM8G89DV7VRPGQE/EasternKingbird.jpg Flycatchers, Shrikes and Vireos - Eastern Kingbird (Copy) Eastern Kingbird - Status: Fairly common summer resident on the plains. - Populations: Though their breeding range overlaps with that of the Western Kingbird, Eastern kingbirds tend to associate more closely with woodlands adjacent to open water. Look for them in woodlands along Boulder Creek and St. Vrain Creek and in cottonwood groves surrounding reservoirs on the plains. - Conservation: Eastern Kingbirds winter in South America and nest from Nevada and British Columbia to the eastern seaboard. Rural development in Colorado, often accompanied by the planting of trees, has provided new breeding opportunities for this wide-ranging kingbird. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186983472-C46KLJ3BLV6DL01R3TTP/LoggerheadShrike.jpg Flycatchers, Shrikes and Vireos - Loggerhead Shrike (Copy) Loggerhead Shrike - Status: Uncommon to rare summer resident of the plains. - Populations: These predatory songbirds nest in open habitats where they capture and impale insects and small mammals on thorns and barbed-wire. They typically place their nests in scattered trees surrounded by grasslands or shrublands. - Conservation: While nesting strikes may have benefited from the planting of trees and construction of barbed-wire fences on the eastern plains, nesting populations have plummeted in Boulder County. Destruction and fragmentation of shortgrass prairies has probably fueled this local decline. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592186992340-WL7P40EP0SMRJCXRTIKR/NorthernShrike.jpg Flycatchers, Shrikes and Vireos - Northern Shrike (Copy) Northern Shrike - Status: Uncommon winter resident on the plains. - Populations: Northern Shrikes nest in the boreal forests of northern Canada, from Alaska east to Labrador. Individuals winter as far south as Arizona, feeding on insects and small mammals. They prefer open country, where they sometimes perch high in snags or sparsely-vegetative trees. - Conservation: No clear trends have been documented in Boulder County numbers since the late nineteenth century. Awesome Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592187001447-EHYZTOVE7H81R9LFE3QP/PlumbeousVireo.jpg Flycatchers, Shrikes and Vireos - Plumbeous Vireo (Copy) Plumbeous Vireo - Status: Fairly common summer resident in open conifer forests in the foothills and low mountains. - Populations: These laid-back, slow-moving vireos are among the easiest songbirds to find in our ponderosa pine woodlands, as they sing from prominent perches and often place their nests near to the ground on dead branches. Their slow, rhythmical song fills our foothills forests throughout the summer. - Conservation: Plumbeous Vireos nest throughout the Rocky Mountains and Great Basin of the western United States and winter in western Mexico. Suppression of natural disturbance (especially fire) in Colorado ponderosa pine forests may create crowded forests unsuitable for nesting. Loss of wintering habitat in Mexico is another potential threat. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592187011416-95V0BZUN3MFICQ2SLDCO/WarblingVireo.jpg Flycatchers, Shrikes and Vireos - Warbling Vireo (Copy) Warbling Vireo - Status: Common summer resident in deciduous woodlands from the plains to around 10,000 feet. - Populations: In Boulder County these sweet-singing vireos nest primarily in cottonwoods on the plains and aspen groves in the foothills. Males sing while on the nest, often located within 12 feet of the ground. - Conservation: Breeding Bird Survey trends show Warbling Vireo populations increasing throughout much of their nesting range, which includes most of the United States and southern Canada. However, loss of aspen groves and pesticide contamination of insect prey pose potential threats to nesting populations. Photo © 2013, Matthew Studebaker https://www.kevinks.com/raptors daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145057240-JUW4AB6YCDBQWBFR1J7U/TurkeyVulture.jpg Vultures, Hawks, Eagles, and Falcons - Turkey Vulture (Copy) Turkey Vulture - Status: Common summer resident and spring and fall migrant. - Populations: Pairs nest in remote caves and crevices in the Flatirons rock formation and foothills canyons. They are so secretive that only three nests have actually been documented in Boulder County. However, as many as 40 non-breeding Turkey Vultures gather in treetop roosts near 4th and University in west Boulder each summer. - Conservation: These adaptive vultures take advantage of road kills and garbage dumps, and their numbers appear to be increasing throughout much of North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145140790-ODI4UQ7FCANADLX3AKBF/Osprey.jpg Vultures, Hawks, Eagles, and Falcons - Osprey (Copy) Osprey (Boulder County isolated or restricted) - Status: Fairly common summer resident and migrant, with a half dozen pairs nesting within the county. - Populations: Pairs nest primarily on artificial nest platforms near prairie reservoirs, including Boulder Reservoir, where 3-4 pairs nest, Longmont Fairgrounds ponds, and Sawhill Ponds. Ospreys nested historically in the mountains of Boulder County, and a pair still nests beside a beaver pond just south of the county line near Rollinsville. - Conservation: Populations have increased dramatically in North America since the banning of DDT in 1972. Boulder County populations continue to increase. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145272662-0IWIGKABTMOONHJOL83M/BaldEagle.jpg Vultures, Hawks, Eagles, and Falcons - Bald Eagle (Copy) Bald Eagle (Boulder County isolated or restricted) - Status: Uncommon summer resident; fairly common winter resident. - Populations: Bald Eagles were first observed nesting in Boulder County in 2002, and 6 pairs nested in 2013. Nests are placed primarily in cottonwoods in riparian areas closed off to human access. Winter populations gather around prairie dog colonies, where they snatch captured prairie dogs from hawks, and also cruise rural areas looking for road-killed deer. - Conservation: Bald Eagle numbers have increased dramatically throughout North America since the banning of DDT in 1972. Construction of reservoirs on the plains of Boulder County has enhanced nesting opportunities here, as has the recent proliferation of road-killed deer. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145423401-EBINXSD0O303CM7TFWV7/NorthernHarrier.jpg Vultures, Hawks, Eagles, and Falcons - Northern Harrier (Copy) Northern Harrier (Boulder County rare and declining nesting populations; isolated) - Status: Rare summer resident; fairly common winter resident. - Populations: Northern Harriers nest primarily in cattail marshes and sedge/rush wetlands on the plains. The only successful Boulder County nests since 1980 have been at wetlands west of Boulder Reservoir and Coot Lake. Harriers are frequently seen in fall and winter as they course low over marshes and grasslands listening for scurrying meadow voles. - Conservation: Once considered a fairly common breeding species in Boulder County, Northern Harrier is now probably our most endangered nesting bird. Successful nesting has been observed only four times during the past 10 years. North American populations are also declining. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145508866-L8LHUS2O5J2WZQ03UYPM/SharpShinnedHawk.jpg Vultures, Hawks, Eagles, and Falcons - Sharp-shinned Hawk (Copy) Sharp-shinned Hawk - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: These small, agile accipiters nest in dense conifer forests from the foothills to the subalpine. Nests are concealed among crowded boughs and are most easily located by listening for the screams of the aggressive adults. Migrating sharpies stream over the foothills throughout April and September. - Conservation: While both the North American Breeding Bird Survey and some hawk migration counts have noted declines in the number of Sharp-shinned Hawks observed, the data are not reliable enough to confirm a clear trend. In Boulder County, maturation of Douglas-fir forests has probably benefited nesting populations. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145604652-3PIXAXAVET8XHU1RX0QW/CoopersHawk.jpg Vultures, Hawks, Eagles, and Falcons - Cooper's Hawk (Copy) Cooper's Hawk - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: Once thought to nest almost exclusively in crowded conifer forests, Cooper's Hawks have recently taken to Boulder County urban areas, including Boulder, Longmont, Louisville, and Lafayette, where they nest in deciduous trees. Pairs still nest in the mountains from the foothills to the subalpine and thousands stream over our hogback ridges during April and September migration. - Conservation: This species has made a dramatic change in its nesting habits during the last couple of decades. Once thought to nest almost exclusively in Boulder County conifer forests, Cooper's Hawks now frequently nest in towns on the plains. No reliable data exists concerning local population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145681002-6U462ZJAE1BXMOON1VCB/CoopersHawkJuvenile.jpg Vultures, Hawks, Eagles, and Falcons - Cooper's Hawk (juvenile) (Copy) Cooper's Hawk (juvenile) - Status: Uncommon summer and winter resident; fairly common migrant. - Populations: Once thought to nest almost exclusively in crowded conifer forests, Cooper's Hawks have recently taken to Boulder County urban areas, including Boulder, Longmont, Louisville, and Lafayette, where they nest in deciduous trees. Pairs still nest in the mountains from the foothills to the subalpine and thousands stream over our hogback ridges during April and September migration. - Conservation: This species has made a dramatic change in its nesting habits during the last couple of decades. Once thought to nest almost exclusively in Boulder County conifer forests, Cooper's Hawks now frequently nest in towns on the plains. No reliable data exists concerning local population trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145757944-3MDFVQ9ZVH5AALWKALT6/NorthernGoshawk.jpg Vultures, Hawks, Eagles, and Falcons - Northern Goshawk (Copy) Northern Goshawk (Boulder County isolated or restricted) - Status: Uncommon year-round resident. - Populations: These secretive and aggressive accipiters nest in tall conifers and aspen groves from the upper foothills to the high subalpine, where they hunt squirrels, mice, and songbirds. A pair has nested recently in a remote area of Heil Ranch Open Space, northwest of Boulder, and several pairs nest in Rocky Mountain National Park and the Indian Peaks Wilderness. - Conservation: During the late 1990s and early 2000s, several pairs nested in the Mountain Park and adjacent foothills west of Boulder. No nests have been detected in this area for several years. This reclusive hawk appears to be particularly sensitive to intrusion into nesting areas by recreational users. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145838247-LBXMQGSEH8P8FK9OKR8I/SwainsonsHawk.jpg Vultures, Hawks, Eagles, and Falcons - Swainson's Hawk (Copy) Swainson's Hawk - Status: Fairly common summer resident. - Populations: Swainson's hawks fly up from Argentina in flocks often numbering several hundred. They nested historically on the prairies of eastern Boulder County, but with many of those areas invaded by trees and Red-tailed Hawks, some pairs have taken to urban open space areas. At least seven pairs nested within the city limits of Broomfield in 2012. - Conservation: Poisoning by insecticides used to control grasshoppers killed tens of thousands of Swainson's Hawks in Argentina during the first decade of this century. Fragmentation of prairies by urbanization and tree invasion has reduced nesting habitat throughout North America. Photo © 2013, Don Whittaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592145989105-SXLZGMW3MVTKXEGQOZQX/RedTailedHawk.jpg Vultures, Hawks, Eagles, and Falcons - Red-tailed Hawk (Copy) Red-tailed Hawk - Status: Common year-round resident. - Populations: This suburban-adapted generalist nests throughout Boulder County, from the plains to the subalpine. Pairs stake out nesting territories wherever there are groves of cottonwoods or other trees and prey on virtually anything that moves, including rodents, birds, and snakes. - Conservation: Numbers of wintering Red-tailed Hawks doubled in Boulder County from 1990-2013, and summer resident populations have probably increased as well. These generalists tend to outcompete other hawks near human settlements. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146060917-2MIJP4U96VVLWTE7VHU7/FerruginousHawk.jpg Vultures, Hawks, Eagles, and Falcons - Ferruginous Hawk (Copy) Ferruginous Hawk - Status: Uncommon winter resident. No nesting has been documented in Boulder County. - Populations: This largest and most regal of North American hawks inhabits prairies and deserts, where it preys on large rodents, including rabbits and prairie dogs. Wintering Ferruginous Hawks gather around prairie dog colonies in northern Boulder County. Look for them around Lagerman Reservoir and at Rabbit Mountain. - Conservation: Fairly common in winter here during the 1980s and early 1990s, Ferruginous Hawk numbers have plummeted as our remaining prairies have been fragmented by non-native trees and expanding towns. North American numbers remained fairly stable from 1966-2011. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146140388-E5R28P80C1X103SF2E96/RoughLeggedHawk.jpg Vultures, Hawks, Eagles, and Falcons - Rough-legged Hawk (Copy) Rough-legged Hawk - Status: Uncommon winter resident on the plains. - Populations: These large, small-taloned hawks nest on the arctic plain, where they prey on small mammals. They winter as far south as California, New Mexico, and Texas. In Boulder County look for them in areas of open grasslands interspersed with wetlands. - Conservation: Numbers observed in winter in Boulder County have declined more than 90% since the early 1990s. Warming temperatures on the plains may be enabling wintering populations to shift farther north; fragmentation of native grasslands and wetlands on the plains of Boulder County may discourage these open country hawks from settling in here during the winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146208514-KMLNPS963SPQ98C3RMQ9/GoldenEagle.jpg Vultures, Hawks, Eagles, and Falcons - Golden Eagle (Copy) Golden Eagle - Status: Fairly common year-round resident. Nests on cliff faces from the lower foothills to the high mountains. - Populations: About 15-20 Golden Eagle pairs nest in Boulder County, constructing their nests on sheer cliffs or occasionally tall trees, especially in the foothills. One nest on the Lefthand Palisades, North of Boulder, has been continuously active since 1885. Golden Eagles range out onto the plains to hunt cottontails, prairie dogs, and other rodents, and many defend foraging territories year-round. - Conservation: North American Breeding Bird Survey data indicate a decline in Golden Eagle numbers throughout North America from 1966-2011. Many are killed by automobiles as they scavenge road-killed prey, and others by collisions with power lines and windmills. Disturbance of cliff nesting habitats remains a concern. Photo © 2013, Kevin McCarthy https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146276982-XHHDFAN347SOVM1PN37T/AmericanKestrel.jpg Vultures, Hawks, Eagles, and Falcons - American Kestrel (Copy) American Kestrel - Status: Common year-round resident. - Populations: These small, colorful falcons nest in woodpecker holes throughout most of Boulder County, including towns on the plains. They prey on small rodents, birds, and insects, especially grasshoppers. - Conservation: Since American Kestrels thrive in urban environments, numbers have increased throughout much of North America. Numbers detected on Boulder County wintering raptor surveys have doubled since 1990. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146342588-JUM6MYOMKKPXN8E1MJNA/PeregrineFalcon.jpg Vultures, Hawks, Eagles, and Falcons - Peregrine Falcon (Copy) Peregrine Falcon (Boulder County rare; isolated or restricted) - Status: Uncommon summer resident; rare spring and fall migrant. - Populations: Fewer than a half-dozen pairs nest on cliff faces, primarily in the foothills, and fly out onto the plains to hunt waterfowl and rodents. Two of the nesting sites are in the Boulder Mountain Park, just southwest of town. - Conservation: After being nearly extirpated throughout North America by DDT poisoning, Peregrine Falcons have bounced back, and North American populations have increased fairly steadily since the early 1970s. They compete with Prairie Falcons and can displace them from nesting sites. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592146421627-FG5LB0K90JZKAEFXCKOY/PrairieFalcon.jpg Vultures, Hawks, Eagles, and Falcons - Prairie Falcon (Copy) Prairie Falcon (Boulder County isolated or restricted) - Status: Uncommon year-round resident. - Populations: A half-dozen or more pairs nest on cliff faces, primarily in the foothills, but cliff nests have been recorded as high as 11,500 feet in Rocky Mountain National Park. Nesting adults fly out onto the plains where they hunt rodents and birds. Look for them perching on telephone poles or bare tree limbs in areas of shortgrass prairie. - Conservation: Nesting numbers in Boulder County appear to have remained steady from 1982-2013, based on annual nest monitoring by Boulder County Nature Association and local parks volunteers. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/tanagers-grosbeaks-buntings-and-blackbirds daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593264620431-T2JS51JK5BAS5O3VOC41/WesternTanager.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Western Tanager (m) (Copy) Western Tanager (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2020, Kevin Smith https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263066103-HQE6X2YR9WZU6Q0RQFVP/WesternTanagerFemale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Western Tanager (f) (Copy) Western Tanager (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263081477-YQ0EXM9TO7RSAKOY1Z9U/Rose-breastedGrosbeak.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Rose-breasted Grosbeak (Copy) Rose-breasted Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263094722-DBN5PNY970AQO88NM4AX/BlackHeadedGrosbeakMale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Black-headed Grosbeak (m) (Copy) Black-headed Grosbeak (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263138297-SOSEOWRZ7SKTVGO4AZ2T/BlueGrosbeak.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Blue Grosbeak (Copy) Blue Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263152089-T9UMMRL883M2LVP4FPSQ/LazuliBunting.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Lazuli Bunting (m) (Copy) Lazuli Bunting (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263163884-PMQC1EL8RJJ50MO0402L/LazuliBuntingFemale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Lazuli Bunting (f) (Copy) Lazuli Bunting (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Ken Cook https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263176642-XDBTNRZE6NMWXGKXKD46/IndigoBunting.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Indigo Bunting (Copy) Indigo Bunting - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263190107-MJ6GNMZEBE7V904FKGPY/Bobolink.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Bobolink (Copy) Bobolink - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263203675-DMC3FRFWRYSDKJORQHNA/RedWingedBlackbirdMale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Red-winged Blackbird (m) (Copy) Red-winged Blackbird (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263214085-KXTE2PLTXFME0SVCMTCJ/RedWingedBlackbirdFemale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Red-winged Blackbird (f) (Copy) Red-winged Blackbird (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263224230-OIYKOBGWTAWZHTHESSTI/WesternMeadowlark.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Western Meadowlark (Copy) Western Meadowlark - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263236327-GQ8JWEE1E1S40697RQHQ/YellowHeadedBlackbird.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Yellow-headed Blackbird (Copy) Yellow-headed Blackbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263246801-O9U8DKXHTKA1ZETPMH00/BrewersBlackbird.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Brewer's Blackbird (Copy) Brewer's Blackbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263258698-JV2KIHSMQ5MBYEQ1UFCK/CommonGrackle.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Common Grackle (Copy) Common Grackle - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Evan Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263270899-RIXCKRNEIW41V8MWTBVB/Great-tailedGrackle.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Great-tailed Grackle (Copy) Great-tailed Grackle - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263280210-JS5PLDCV7IBIWYDXKO65/Brown-headedCowbird.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Brown-headed Cowbird (Copy) Brown-headed Cowbird - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263290316-QM4V79042O3PNBG1TCCI/BullocksOrioleMale.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Bullock's Oriole (m) (Copy) Bullock's Oriole (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593263304425-5F2P5U4C2DD47ORJM0U4/OrchardOriole.jpg Tanagers, Grosbeaks, Buntings and Blackbirds - Orchard Oriole (Copy) Orchard Oriole - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://www.kevinks.com/warblers daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225328496-21Y2B8GLADJAPJXJA1C3/OrangeCrownedWarbler.jpg Warblers - Yellow-crowned Warbler (Copy) Yellow-crowned Warbler - Status: Fairly common migrant, plains, foothills, and mountains. - Populations: One of the earliest migrating warblers to appear in spring, often heard singing in riparian and shrubby areas in the foothills by late April. Nests in brushy woodlands and forest edges from New Mexico and Colorado (west slope only) and California north to Alaska and Newfoundland. - Conservation: Breeding Bird Survey data indicated a 1.9% decline throughout the United States from 1966-2012. Encroachment of human habitations into shrubby areas and forest edges may have reduced nesting habitat. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225342606-XUXBEEGJC4LLFEKA8E56/VirginiasWarbler.jpg Warblers - Virginia's Warbler (Copy) Virginia's Warbler - Status: Fairly common summer resident of open forests, foothills and mountains. - Populations: One of our most common warblers, though more often heard than seen as it sings (a weak, lazy, "see-see-see-see-see-see, see-see, see"--descending slightly and then rising at the end) from perches in conifers in open forests of the foothills and low mountains. Nests on the ground under shrubs throughout the southern Rocky Mountains and Great Basin region. - Conservation: Doing very well in Boulder County, where increased shrub growth in the foothills after the removal of grazing cattle has enriched nesting habitat. In contrast, fire suppression in mountain conifer forests has reduced nesting habitat by suppressing shrub growth. Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225354603-ZNETSZYTKGRE4RC721BH/YellowWarbler.jpg Warblers - Yellow Warbler (Copy) Yellow Warbler - Status: Common summer resident in riparian woodlands; plains, foothills, and mountains. - Populations: Common in deciduous woodlands from the plains to about 8500 feet. Easily identified by its breathy, descending "sweet-sweet-sweet, I'm so very sweet" song, often delivered from high in a cottonwood. Nests throughout North America from Alaska south to central Mexico. - Conservation: Boulder County nesting populations have thrived as deciduous woodlands proliferate along prairie streams and in urban settlements. Breeding Bird Survey data indicate that populations throughout North America remain stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225385273-F109ALKL9QC8TJGOTEJ0/YellowRumpedWarbler.jpg Warblers - Yellow-rumped Warbler (Copy) Yellow-rumped Warbler - Status: Common summer resident in foothill and mountain conifer forests. - Populations: These colorful mountain warblers nest in conifer forests at virtually all elevations, from central Mexico north to Alaska and Newfoundland. Their Boulder County nesting range overlaps in the foothills and lower mountains with that of Virginia's warbler, whose song they may "adopt," sometimes rendering identification by ear challenging. - Conservation: Abundant in conifer forests from 7500-11,000 ' and probably our most common Boulder County warbler. Nesting populations appear stable throughout most of the mountains of western North America. Still one of our most common migrants on the plains and in the foothills in May and September. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225397420-M9UYILWANW0ZI5AV9FEE/TownsendsWarbler.jpg Warblers - Townsend's Warbler (Copy) Townsend's Warbler - Status: Uncommon migrant, primarily in mountain forests. - Populations: Observed primarily in August and September as adults and fledglings move southward through mountain forests toward Mexico and Central America. Nests in conifer forests of northwestern North America, from Wyoming to Alaska. - Conservation: Breeding Bird Survey results indicate that North American nesting populations are stable. Number observed in Colorado during migration probably depends in part on availability of insects in mountain conifer forests. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225409210-734ESYQ8EQB832NVN5DP/AmericanRedstart.jpg Warblers - American Redstart (Copy) American Redstart - Status: Rare migrant, primarily in plains riparian woodlands. - Populations: Nests primarily in deciduous forests and second-growth woodlands from Florida north to Newfoundland, Yukon Territory, and Southeast Alaska. Each spring and early summer, a few males are heard singing in foothills deciduous woodlands of Boulder County, but nesting has never been documented here. Most easily found by the male's distinctive song, a series of high, thin notes usually followed by a down-slurred note. - Conservation: Since they thrive in open deciduous habitats, American redstarts have benefited from clearing of some forest areas. However, loss of deciduous woodlands throughout much of eastern North America has impacted nesting populations, and Breeding Bird Survey data show a statistically significant decline of 1.5%/year throughout the United States from 1966-2012. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225422095-OUV3VSN5J5VDTFP1MJFJ/Ovenbird.jpg Warblers - Ovenbird (Copy) Ovenbird - Status: Uncommon summer resident in foothills canyons. - Populations: Pairs use leaf litter to build their oven-shaped nests on the ground, from the southeastern United States westward to the Rockies and north into central Canada. Though not uncommon in Gambel oak woodlands of the southern Front Range, nesting pairs appear rare in Northern Colorado, where absence of oak leaf litter makes nest building a challenge. Here in Boulder County we observe several singing males each spring and early summer but have never documented nesting. - Conservation: North American populations appear to be stable. Numbers appear to have increased in western Nebraska and along the Colorado Front Range as deciduous tree and shrub growth has proliferated in canyon areas. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225433920-TAUJXCENAYVZFYZCHGKB/MacGillivraysWarbler.jpg Warblers - MacGillivray's Warbler (Copy) MacGillivray's Warbler - Status: Fairly common summer resident in foothills riparian woodlands and mountain willow carrs. - Populations: Listen for the short (usually seven notes or fewer), churry warbles of these ground-nesters along foothill and mountain streams from 6500-10,500'. Their call is a sharp, harsh tsik, similar but slightly lighter than that of dark-eyed juncos. They nest throughout the mountains of western North America wherever dense undergrowth is available. - Conservation: Ski area construction and other disturbances of mountain willow carrs and montane shrublands have reduced available nesting habitat in Colorado. Breeding Bird Survey data indicate a statistically significant 0.8%/year decline in populations throughout the United States from 1966-2012. Photo © 2013, Glenn Bartley https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225447065-7MMMEZLOTV82P033K1EP/CommonYellowthroat.jpg Warblers - Common Yellowthroat (Copy) Common Yellowthroat - Status: Common summer resident in marshes and willow carrs, plains to mid-elevation mountains. - Populations: The sweet, loud "wichity, wichity, wichity," song of these bright yellow and brown warblers resonates in cattail marshes and other wetlands on the plains throughout late spring and early summer. Nests on the ground in dense vegetation. - Conservation: Proliferation of cattail marshes around gravel mining areas has probably benefited these marsh-nesting warblers in Boulder County, though most of the original wetlands where they nested historically have been destroyed. Breeding Bird Survey data indicate a 1.0%/year decline throughout North America from 1966-2012. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225461725-E94FOV6AYYRG72U4YGKS/WilsonWarbler.jpg Warblers - Wilson's Warbler (Copy) Wilson's Warbler - Status: Fairly common summer resident in wet mountain forests and willow carrs. - Populations: These active, yellow-faced warblers nest in dense bogs and willow thickets, primarily above 8500'. Their song is a series of chee notes, generally on the same pitch and slower than the song of yellow warblers. They nest in boreal wetlands of North America from Colorado and California north to Alaska and Northwest Territories, and across central and northern Canada to Newfoundland. - Conservation: Breeding Bird Survey data indicate a 1.8%/year decline throughout North America from 1966-2012. Destruction and fragmentation of mountain willow carrs by various human activities can reduce nesting populations. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593225472706-249IGLI3D1HRW76WOCUO/Yellow-BreastedChat.jpg Warblers - Yellow-breasted Chat (Copy) Yellow-breasted Chat - Status: Common summer resident, plains and foothills shrublands. - Populations: These medium-sized, thick-billed insectivores in the genus Icteria were once considered to be warblers, but are probably best placed in a group all their own. Males perch prominently in foothill shrubs, emitting an unrelenting stream of whistles, grunts, squawks, chattering clucks, and rattles. Males often sing right through the night. - Conservation: Nesting populations have probably increased at the base of the Boulder County foothills as grazing cattle were removed from shrubby areas. Breeding Bird Survey data indicate a 0.6%/year decline throughout North America from 1966-2012. Photo © 2013, Ken Cook https://www.kevinks.com/banner-images daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904852020-3A3LIS6RROOOL223THSK/image-asset.jpeg Banner Images - Female and Male Northern Shovelers (Copy) Female and Male Northern Shovelers https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904912365-0ZN5CPS7QSWIUUYJRBRS/image-asset.jpeg Banner Images - American White Pelican in flight (Copy) American White Pelican in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588904996329-2T5K5K1Z4UL4IP8NDTJU/image-asset.jpeg Banner Images - Wilson's Snipe (Copy) Wilson's Snipe https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905048292-DIOZA9LXVOBERMA4YG8P/image-asset.jpeg Banner Images - Sandhill Crane in flight (Copy) Sandhill Crane in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905084315-RZE6DE1MFA3RYIUMKJ9P/image-asset.jpeg Banner Images - Snow Goose in flight (Copy) Snow Goose in flight https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905135923-GVRXTZD45RUOLO8NDHCK/image-asset.jpeg Banner Images - Greater Yellowlegs scaring minnows (Copy) Greater Yellowlegs scaring minnows https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905198484-O7ADBAQRB8JFCTWAQHUH/image-asset.jpeg Banner Images - Broad-tailed Hummingbird (Copy) Broad-tailed Hummingbird https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905247265-RBD80KJ9FQIUY2CJVX0Y/image-asset.jpeg Banner Images - Gray-headed Rosyfinch (Copy) Gray-headed Rosyfinch https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588905284544-770JC802DPUZSK6ZZHRS/image-asset.jpeg Banner Images - Singing Yellow-headed Blackbird (Copy) Singing Yellow-headed Blackbird https://www.kevinks.com/finches daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265265053-3BK6CQOB5Y4ZOXXDTPX3/Gray-CrownedRosyFinch.jpg Finches - Gray-crowned Rosy Finch (Copy) Gray-crowned Rosy Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Ken Cook https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265280043-S6SAQ1P3V340YYR4NJAI/Brown-cappedRosyFinch.jpg Finches - Brown-capped Rosy Finch (Copy) Brown-capped Rosy Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265293046-HBG00N507BJE4VNI3YPZ/PineGrosbeak.jpg Finches - Pine Grosbeak (Copy) Pine Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265305447-M0G7HY1HDCVBQJY315K2/CassinsFinch.jpg Finches - Cassin's Finch (Copy) Cassin's Finch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265316409-M6KM4NSVQP9WC7WYAKV5/HouseFinchMale.jpg Finches - House Finch (m) (Copy) House Finch (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265329220-7CMPF52RHF9O518IE6TZ/HouseFinchFemale.jpg Finches - House Finch (f) (Copy) House Finch (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265341848-W012NKC7T60N0NRV5TCL/RedCrossbillDuplicate.jpg Finches - Red Crossbill (Copy) Red Crossbill - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265353076-ALU6JSZV1C0OZJI7DOAN/PineSiskin.jpg Finches - Pine Siskin (Copy) Pine Siskin - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Don Brockmeier https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265364465-VJ2VXDGZCQI0ZAK43ID7/LesserGoldfinch.jpg Finches - Lesser Goldfinch (Copy) Lesser Goldfinch - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Jay Mahoney https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265376798-6VNH37W2Q0QEJC8TV3GN/AmericanGoldfinchMale.jpg Finches - American Goldfinch (m) (Copy) American Goldfinch (m) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265393988-1QIJZP74MIM3JMHR0PXH/AmericanGoldfinchFemale.jpg Finches - American Goldfinch (f) (Copy) American Goldfinch (f) - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265405865-G2UXL6NJGEU4X7Z36G60/EveningGrosbeakMale.jpg Finches - Evening Grosbeak (Copy) Evening Grosbeak - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1593265422271-P4DJ41V7HC2RO8D7A2HI/HouseSparrow.jpg Finches - House Sparrow (Copy) House Sparrow - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2013, Kevin McCarthy https://www.kevinks.com/corvids daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771380378-P8LVRR5AX9MO5S6X8VZX/GrayJay.jpg Corvids - Gray Jay (Copy) Gray Jay - Status: Fairly common year-round resident of high mountain conifer forests. - Populations: These garrulous mountain jays nest in conifer forests from about 8500' to treeline. They mix scavenged food with saliva, roll it into a ball, and store this bolus on a limb under bark or lichens. They are attracted to humans and will snatch sandwich bits out of your hand if you're not watching carefully. - Conservation: Numbers appear to be stable in Colorado, and no changes in their overall statewide range have been noted since 1900. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771397816-DAWXHK3XHKTLC638D4XX/StellersJay.jpg Corvids - Steller's Jay (Copy) Steller's Jay - Status: Very common year-round resident, primarily in foothills and mountain conifer forests. - Populations: These audacious jays inhabit conifer forests throughout Colorado, where they feed on insects, scavenge food scraps, and occasionally rob other birds' nests of eggs and young. They are readily attracted to humans and our picnic leavings and often follow hikers and skiers through the woods. - Conservation: Steller's Jays appear to be thriving throughout their historical Colorado range as they adapt to humans and our bird feeders and table scraps. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771410578-9UV0S4JMEUFEG3RH109D/BlueJay.jpg Corvids - Blue Jay (Copy) Blue Jay - Status: Common year-round resident in urban areas and riparian woodlands on the plains. - Populations: Originally inhabitants of mixed deciduous forests, these adaptable jays have followed deciduous trees westward and learned to live among humans in urban areas. More than 75% of their food comes from vegetable matter, including nuts, acorns, seeds, berries, and other fruit. They typically nest in deciduous trees or shrubs. - Conservation: Blue Jays were first reported in Colorado in 1903 and first reported nesting in 1905 near Yuma. They eventually reached virtually all the northern Front Range cities and have begun to move up into the mountains, where they sometimes hybridize with native Steller's Jay's. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771422605-A5ZK95G7Z0RNEFPV24UX/WoodhousesScrubJay.jpg Corvids - Woodhouse's Scrub Jay (Copy) Woodhouse's Scrub Jay - Status: Fairly common year-round resident in shrub communities, primarily at the base of the foothills. - Populations: Historically, Woodhouse’s Scrub-jays were reported primarily in scrub-oak woodlands, primarily on the Western Slope. Recently they have spread into shrublands throughout the Front Range foothills and much of southeastern Colorado. They nest in shrub thickets where they feed on acorns, piñon nuts, and other fruits and seeds. However, during the nesting season they may feed primarily on insects. - Conservation: Numbers appear to be stable throughout most of their Colorado nesting range, although populations continue to expand east of the mountains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771431977-6U79ZWH7OMPL956FWAT9/ClarksNutcracker.jpg Corvids - Clark's Nutcracker (Copy) Clark's Nutcracker - Status: Fairly common year-round resident of high mountain conifer forests. - Populations: These large, resourceful jays nest primarily in spruce-fir and other mixed conifer forests above 8000 feet, where they feed on seeds, berries, insects, small mammals, and carrion. A single individual can carry 70 are more seeds in its sublingual pouch and may cache up to 10,000 seeds (primarily in the ground) during a single season. - Conservation: Because nutcrackers are so wide-ranging and their nests not particularly easy to find, little is known about population trends in Colorado. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771440587-VKQQV2TOXXP7BO78AU24/BlackBilledMagpie.jpg Corvids - Black-billed Magpie (Copy) Black-billed Magpie - Status: Very common year-round resident of shrublands, riparian woodlands, and open conifer forests from the plains to the high mountains. - Populations: Black-billed magpies nest in shrublands, open conifer forests, woodlands, and urban edges throughout Colorado. They build mud and stick nests surrounded by globular stick structures, and they feed on pretty much anything they can find, including insects, wild fruits, and carrion. They often perch on the backs of deer, elk, and livestock, where they feed on ticks. - Conservation: Paradoxically, Breeding Bird Survey data show this cosmopolitan species decreasing in North America, including on the High Plains. Magpies' intolerance of high summer heat levels may partially explain this observed decline. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771450500-CSZARX9OMG5MS8S3CWWZ/AmericanCrow.jpg Corvids - American Crow (Copy) American Crow - Status: Very common year-round resident from the plains to the high mountains; thrives in urban areas. - Populations: American Crows nest from the plains to up to 10,000 feet, traveling in enormous flocks in winter but usually separating out into breeding pairs in spring and summer. They build their nests in trees, shrubs, or on utility poles and scavenge fruits, insects, and carrion. - Conservation: Crows thrive wherever humans live, and Breeding Bird Survey data show a gradual population increase nationally. In Colorado crows have expanded their range into urban and suburban areas, especially in the southern half of the state. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592771462014-2SA95C2EYMKAT2P4GNDI/CommonRaven.jpg Corvids - Common Raven (Copy) Common Raven - Status: Very common year-round resident, plains and foothills. Nests primarily on cliffs and thrives around urban areas. - Populations: Common Ravens breed primarily in mountain forests, though in recent years more pairs have nested in suburban areas on the plains. They eat carrion, small rodents, insects, wild fruits, and grains. They nest primarily on cliffs but also in trees and on power poles. - Conservation: Considered rare in eastern Colorado during the late 19th century, ravens have spread up and down the Front Range, taking advantage of road-kills and other food provided by humans. Believe it or not, Chihuahuan Ravens were more abundant than Common Ravens in Boulder County during the first half of the 20th century. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/chickadees daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775286145-W5SIV5AALOE1AJ92O71H/BlackCappedChickadee.jpg Chickadees, Nuthatches and Creeper - Black-capped Chickadee (Copy) Black-capped Chickadee - Status: Common year-round resident on the plains and in mountain aspen groves. - Populations: We tend to associate these perky chickadees with riparian woodlands on the plains, but surprisingly most nesting pairs are found in aspen groves and riparian woodlands in the mountains. They excavate their own cavity-nests in soft bark and line them with fiber, moss, cocoons, feathers, wool, and hair. - Conservation: Suppression of natural fires has reduced nesting opportunities in ponderosa pine woodlands in the foothills. Across North America, breeding populations appear to be increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775299093-JAYQVW0WLB4U53RE9WX7/MountainChickadee.jpg Chickadees, Nuthatches and Creeper - Mountain Chickadee (Copy) Mountain Chickadee - Status: Common year-round resident in conifer forests. - Populations: Much more abundant in Colorado than black-caps, Mountain Chickadees nest primarily in conifer forests from the low foothills to near tree line. About 20% of nests are in aspen woodlands. They excavate their own nest cavities and stuff them with bark, moss, and animal fur. Recent studies show that chickadees have complex languages, with dozens of different call sequences used to indicate varying degrees of danger and even name individual predators. - Conservation: These human-tolerant cavity-nesters seem to be thriving throughout the mountains of Colorado, though fire suppression and removal of old or rotting trees has reduced nesting opportunities in many forests. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775309758-2TCXXSCWRV30ISOUJHW8/Bushtit.jpg Chickadees, Nuthatches and Creeper - Bushtit (Copy) Bushtit - Status: Uncommon to fairly common year-round resident of shrublands in and near the foothills. - Populations: Considered rare in Boulder County until quite recently, Bushtits have moved up into our foothills shrublands from the south, expanding their documented nesting range northward by at least 100 miles. In March they begin working on pendulous, oriole-like nests, which they hang from shrubs or small trees. Throughout the nesting process, pairs accept assistance from other adults and juveniles in raising young. - Conservation: Bushtits breed from southern British Columbia, southern Idaho, and Wyoming south to Guatemala. In Colorado highest densities of nesting pairs occur in piñon/juniper woodlands in the western valleys. Photo © 2013, Matthew Studebaker https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775320443-B71H80ISL2BFIFG5FNVA/RedBreastedNuthatch.jpg Chickadees, Nuthatches and Creeper - Red-breasted Nuthatch (Copy) Red-breasted Nuthatch - Status: Fairly common year-round inhabitant of mountain conifer forests. - Populations: These vocal and colorful cavity-nesters breed primarily in conifer forests and aspen groves from the foothills to treeline. They wander throughout the mountains seeking out abundant conifer cone crops. - Conservation: Red-breasted Nuthatches nest from southeastern Alaska across southern Canada to the northern United States, including most of the western mountain ranges. While forest management has reduced the availability of snags for nesting in many areas, invasion of mature aspen forests by conifers has created near ideal nesting habitat, since these nuthatches typically forage in conifers but may prefer to excavate their nest cavities in aspens. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775329920-9A05SZ0P5Q2ZHN2CZZ8F/WhiteBreastedNuthatch.jpg Chickadees, Nuthatches and Creeper - White-breasted Nuthatch (Copy) White-breasted Nuthatch - Status: Fairly common year-round resident of conifer forests, aspen groves, and plains riparian woodlands. - Populations: These relatively cosmopolitan nuthatches lay their eggs in cracks or woodpecker holes in conifers, aspens, and even cottonwoods, from the plains to around 10,000 feet. Inside the cavity, they construct a nest consisting of a layer of bark strips, a layer of dried earth or mud, and some animal fur. - Conservation: White-breasted nuthatches nest up to 10,000 feet virtually wherever there are trees of some kind--across southern Canada, the lower 48 states, and south to southern Mexico. In Colorado only a few pairs nest on the eastern plains, with highest nesting concentrations occurring in the foothills and lower mountains. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775341028-PVSE03WHDGLRMYURB2CQ/PygmyNuthatch.jpg Chickadees, Nuthatches and Creeper - Pygmy Nuthatch (Copy) Pygmy Nuthatch - Status: Common year-round resident in ponderosa pine forests. - Populations: Considered an "indicator species" of ponderosa pine woodlands and forests, Pygmy Nuthatches typically excavate their own nest cavities in ponderosas or other pines. They feed primarily on insects gleaned from the outer needles and twigs of the pines, often dangling upside down as they forage. - Conservation: These habitat specialists live year-round in pine forests from British Columbia to southern Mexico. This means that considerable numbers probably have occupied Colorado for only about 10,000 years, as ponderosa pines did not appear here until after the last ice age. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592775352648-GJYG4SOHLPIZHLXJQLDM/BrownCreeper.jpg Chickadees, Nuthatches and Creeper - Brown Creeper (Copy) Brown Creeper - Status: Fairly common year-round resident of mountain conifer forests, aspen groves, and plains riparian woodlands. - Populations: Listen for the very high-pitched, shrill calls of these active foragers as they spiral their way up conifer tree trunks from the lower foothills to the high mountains. They feed on spiders, beetles, moths, and other insects. Brown Creepers suspend hammock-like nests behind pieces of bark peeling away from dead or dying conifers. In winter look and listen for them in cottonwoods along prairie streams. - Conservation: Brown Creepers breed throughout most of North America, but usually in modest numbers. They may do best in mature to old-growth conifer forests containing lots of large, dead or dying trees. Photo © 2013, Gerhard Assenmacher https://www.kevinks.com/swans-geese-ducks daily 0.75 2024-08-30 https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588733920805-JU3ER89QCMGH384MV3LL/image-asset.jpeg Swans, Geese, Ducks - American Wigeon (m) (Copy) American Wigeon (m) - Status: Uncommon summer resident; common to abundant migrant and winter resident. - Populations: Nesting in Boulder County is poorly documented, but a few pairs appear to remain here throughout the summer. Breeding numbers are most concentrated from the Dakotas north and west to Alaska. Large flocks gather on prairie ponds, reservoirs, and streams in Boulder County from September-April. Look for them on Boulder Creek next to the Boulder Public Library and at Walden and Sawhill ponds. - Conservation: After a decade of decline during the 1980s, North American populations recovered to near-historic high levels of more than 3 million by 2000. Nesting success in eastern Colorado may be limited by lack of protective vegetation around lakes and reservoirs, as well as predation by bull snakes. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588734292418-LDTI1B9XK0HDLBUV08LJ/image-asset.jpeg Swans, Geese, Ducks - American Wigeon (f) (Copy) American Wigeon (f) - Status: Uncommon summer resident; common to abundant migrant and winter resident. - Populations: Nesting in Boulder County is poorly documented, but a few pairs appear to remain here throughout the summer. Breeding numbers are most concentrated from the Dakotas north and west to Alaska. Large flocks gather on prairie ponds, reservoirs, and streams in Boulder County from September-April. Look for them on Boulder Creek next to the Boulder Public Library and at Walden and Sawhill ponds. - Conservation: After a decade of decline during the 1980s, North American populations recovered to near-historic high levels of more than 3 million by 2000. Nesting success in eastern Colorado may be limited by lack of protective vegetation around lakes and reservoirs, as well as predation by bull snakes. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588736030696-EVX3DEKG8JQD0HLKE6OJ/image-asset.jpeg Swans, Geese, Ducks - Blue-winged Teal (m) (Copy) Blue-winged Teal (m) - Status: Fairly common summer resident and spring and fall migrant. - Populations: These dabblers gravitate to shallow ponds and mud flats. They nest on the ground amid concealing grasses or other low vegetation, sometimes far from water. Successful nesting in Boulder County is uncommon. They winter from California south to Brazil and Peru. Look for the first spring arrivals in March at Walden and Sawhill Ponds, Boulder Reservoir, and Baseline Reservoir. - Conservation: Second most abundant duck in North America. North American populations reached a 40-year low in 1990 after a period of drought on the northern plains. Numbers have more than doubled since then. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588736254127-YQO51H6YUGU7KKA77R14/image-asset.jpeg Swans, Geese, Ducks - Blue-winged Teal (f) (Copy) Blue-winged Teal (f) - Status: Fairly common summer resident and spring and fall migrant. - Populations: These dabblers gravitate to shallow ponds and mud flats. They nest on the ground amid concealing grasses or other low vegetation, sometimes far from water. Successful nesting in Boulder County is uncommon. They winter from California south to Brazil and Peru. Look for the first spring arrivals in March at Walden and Sawhill Ponds, Boulder Reservoir, and Baseline Reservoir. - Conservation: Second most abundant duck in North America. North American populations reached a 40-year low in 1990 after a period of drought on the northern plains. Numbers have more than doubled since then. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772337331-T4EDIVXNOJGGCL07PWBF/image-asset.jpeg Swans, Geese, Ducks - Canada Goose (Copy) Canada Goose - Status: Abundant year-round resident. - Populations: Flocks of hundreds to thousands of individuals inhabit ponds, agricultural fields, golf courses, and urban parks. Some stay year-round, others migrate north in summer or south and winter. - Conservation: Once rare in Boulder County, this cosmopolitan goose has adapted to suburban and rural life, taking advantage of seeds and invertebrates found in lawns, parks, and agricultural fields. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772460011-QV9UO1R4BSJS1X29FHTO/image-asset.jpeg Swans, Geese, Ducks - Cinnamon Teal (m) (Copy) Cinnamon Teal (m) - Status: Fairly common summer resident and spring migrant. Uncommon fall migrant. - Populations: These striking dabblers nest in similar sites to those used by Blue-winged Teal, and the two species are often seen together. Look for them out Walden Ponds, Boulder Reservoir, and Union Reservoir. In early fall, they migrate south to Mexico and South America. - Conservation: With a total North American population of around 300,000, this is one of our least, and dabbling ducks. Nesting success in Boulder County is limited by nest predation and a paucity of favorable nest sites. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772512183-KIP8JTKKYEGKE3775KR1/image-asset.jpeg Swans, Geese, Ducks - Cinnamon Teal (f) (Copy) Cinnamon Teal (f) - Status: Fairly common summer resident and spring migrant. Uncommon fall migrant. - Populations: These striking dabblers nest in similar sites to those used by Blue-winged Teal, and the two species are often seen together. Look for them out Walden Ponds, Boulder Reservoir, and Union Reservoir. In early fall, they migrate south to Mexico and South America. - Conservation: With a total North American population of around 300,000, this is one of our least, and dabbling ducks. Nesting success in Boulder County is limited by nest predation and a paucity of favorable nest sites. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772618369-HM98LBCHKWIHU5HSA7PD/image-asset.jpeg Swans, Geese, Ducks - Gadwall (m) (Copy) Gadwall (m) - Status: Uncommon summer resident; common winter resident and migrant. - Populations: A few pairs may nest each spring along the shores of our larger ponds and reservoirs on the plains. Large flocks gather on prairie ponds and reservoirs throughout the fall, winter, and spring. Listen for the deep grunting calls of the males. The first pond on the right at Sawhill Ponds supports 100 or more Gadwalls from March-April and October-December. - Conservation: North American populations more than doubled from 1986-1996 as wetlands were protected and enhanced throughout the Prairie Pothole Region and central Great Plains. Boulder County nesting populations are greatly limited by an absence of lakes with shallow, grassy shorelines for concealing nests. Bull snakes probably prey heavily on nests throughout eastern Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772684922-JNMLXICHUWHUTZ4MYUG3/image-asset.jpeg Swans, Geese, Ducks - Gadwall (f) (Copy) Gadwall (f) - Status: Uncommon summer resident; common winter resident and migrant. - Populations: A few pairs may nest each spring along the shores of our larger ponds and reservoirs on the plains. Large flocks gather on prairie ponds and reservoirs throughout the fall, winter, and spring. Listen for the deep grunting calls of the males. The first pond on the right at Sawhill Ponds supports 100 or more Gadwalls from March-April and October-December. - Conservation: North American populations more than doubled from 1986-1996 as wetlands were protected and enhanced throughout the Prairie Pothole Region and central Great Plains. Boulder County nesting populations are greatly limited by an absence of lakes with shallow, grassy shorelines for concealing nests. Bull snakes probably prey heavily on nests throughout eastern Colorado. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772730803-KBW0AUXAQKNGW6RWDM4M/image-asset.jpeg Swans, Geese, Ducks - Greater White-fronted Goose (Copy) Greater White-fronted Goose - Status: STATUS - Populations: POPULATIONS - Conservation: CONSERVATION Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772824106-YSL3CTXWHTRLVWD2H0RW/image-asset.jpeg Swans, Geese, Ducks - Mallard (m) (Copy) Mallard (m) - Status: Abundant year-round resident. - Populations: These urban-adapted ducks nest on shorelines of streams, ponds, and reservoirs in Boulder County from the plains to the subalpine. They breed throughout North America from the U.S./Mexico border north to the Subarctic. - Conservation: More than 10 million currently breed in North America. Populations are stable or increasing throughout much of their breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772889832-ZZVK7HBDBXXLTUWZIY4N/image-asset.jpeg Swans, Geese, Ducks - Mallard (f) (Copy) Mallard (f) - Status: Abundant year-round resident. - Populations: These urban-adapted ducks nest on shorelines of streams, ponds, and reservoirs in Boulder County from the plains to the subalpine. They breed throughout North America from the U.S./Mexico border north to the Subarctic. - Conservation: More than 10 million currently breed in North America. Populations are stable or increasing throughout much of their breeding range. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1588772992744-CQDLC2HR3Q57FT3LM61B/image-asset.jpeg Swans, Geese, Ducks - Northern Shoveler (m) (Copy) Northern Shoveler (m) - Status: Uncommon summer resident, abundant to fairly common migrant and winter resident. - Populations: Northern Shovelers frequent shallow water of streams, ponds, and reservoirs. Look for them in spring and fall at Walden Ponds, Baseline Reservoir, and Union Reservoir. They nest from Colorado north through the Prairie Pothole region to Northwestern Canada and Alaska. Nesting in Boulder County is poorly documented. - Conservation: Loss of more than half of waterfowl nesting habitat throughout North America since the 1700s have hurt this and other species. About 150,000-200,000 Northern Shovelers are killed each year by hunters. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998403706-4N36PUADQ3U10EGMONMP/northernshoveler2.jpg Swans, Geese, Ducks - Northern Shoveler (f) (Copy) Northern Shoveler (f) - Status: Uncommon summer resident, abundant to fairly common migrant and winter resident. - Populations: Northern Shovelers frequent shallow water of streams, ponds, and reservoirs. Look for them in spring and fall at Walden Ponds, Baseline Reservoir, and Union Reservoir. They nest from Colorado north through the Prairie Pothole region to Northwestern Canada and Alaska. Nesting in Boulder County is poorly documented. - Conservation: Loss of more than half of waterfowl nesting habitat throughout North America since the 1700s have hurt this and other species. About 150,000-200,000 Northern Shovelers are killed each year by hunters. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591977555277-MU1PSL0XXQP8RVNF6IXW/image-asset.jpeg Swans, Geese, Ducks - Snow Goose in flight (Copy) Snow Goose in flight - Status: Uncommon migrant and rare winter visitor. - Populations: Stray individuals sometimes mix in with large flocks of Canada Geese during winter. Listen for large flocks passing high overhead in early spring and late fall. In winter, look for individuals at Valmont Reservoir and the White Rocks area. Up to 50,000 gather along the North Platte River between Oshkosh and Lake McConaghy in March. - Conservation: Nests from eastern Siberia across arctic plains of Alaska and Canada to Greenland. Total population may exceed 8,000,000, and increasing numbers have stressed Arctic breeding areas since pairs are reluctant to stray far from their home colonies. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591977754445-B70JVFSOZHSF0SNEKCMI/image-asset.jpeg Swans, Geese, Ducks - Trumpeter Swan with young (Copy) Trumpeter Swan with young - Status: Rare migrant and winter visitor - Populations: A few stray individuals and small groups may appear on local lakes and reservoirs in late fall, rarely lingering through early spring. Look for them at Baseline Reservoir, Boulder Reservoir, Marshall Ponds, and Walden Ponds. Pairs nest on muskrat houses or on the banks of prairie lakes and marshes from Nebraska northward into central Canada. - Conservation: Recovering from near-extinction during the early 20th century. About 150,000 were counted in 2012. Photo © 2013 Steve Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998151855-XNJ8T2NGA7ZN3T4W6J5P/tundraswan11.jpg Swans, Geese, Ducks - Tundra Swan (Copy) Tundra Swan - Status: Rare migrant and winter visitor. - Populations: A few stray individuals and small groups may appear on local lakes and reservoirs in late fall, and sometimes a few stick around through early spring. A flock of 15 wintered at Valmont Reservoir in 2012-13. Look for them also at Baseline Reservoir and Boulder Reservoir. Pairs nest on the arctic tundra and winter in the Great Basin and along the West Coast. - Conservation: North American populations have been increasing and now stand at around 200,000. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998240769-N1Z8ZASTM1SULM4KTD5L/woodduck11.jpg Swans, Geese, Ducks - Wood Duck (m) (Copy) Wood Duck (m) - Status: Fairly common summer resident; rare to uncommon in winter. - Populations: Look for nesting pairs along Saint Vrain Creek and Boulder Creek east of the foothills, where females lay eggs in abandoned woodpecker holes and larger tree cavities. In winter, look for the brightly colored males along Boulder Creek near the Boulder Public Library and east of Sawhill Ponds. - Conservation: Wood Ducks have increased throughout much of Colorado as cottonwoods and other deciduous trees have proliferated along streams on the prairie and in the western valleys. North American populations were severely endangered by overhunting during the late nineteenth and early twentieth centuries, but they have recovered impressively. North American populations currently appear to be stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998329229-39SHULGUKQMUDFF5ZK26/woodduck31.jpg Swans, Geese, Ducks - Wood Duck (f) (Copy) Wood Duck (f) - Status: Fairly common summer resident; rare to uncommon in winter. - Populations: Look for nesting pairs along Saint Vrain Creek and Boulder Creek east of the foothills, where females lay eggs in abandoned woodpecker holes and larger tree cavities. In winter, look for the brightly colored males along Boulder Creek near the Boulder Public Library and east of Sawhill Ponds. - Conservation: Wood Ducks have increased throughout much of Colorado as cottonwoods and other deciduous trees have proliferated along streams on the prairie and in the western valleys. North American populations were severely endangered by overhunting during the late nineteenth and early twentieth centuries, but they have recovered impressively. North American populations currently appear to be stable. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143147437-DG77425FN3JIDZIE795C/NorthernPintailMale.jpg Swans, Geese, Ducks - Northern Pintail (m) (Copy) Northern Pintail (m) - Status: Uncommon to rare summer resident; fairly common migrant and winter resident. - Populations: Small numbers of Northern Pintails mix in with flocks of other dabblers on prairie ponds and reservoirs throughout eastern Colorado. They breed from northern Colorado north through much of Canada to Alaska. Nesting in Boulder County is poorly documented. They winter from British Columbia and New Mexico south to Central America. - Conservation: North American populations approached 10 million during the 1960s, then plummeted to 2-4 million during the drought years of the early 1990s. Numbers appear to be recovering. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143238023-AH7AFGVFWB6P9XGR66CY/NorthernPintailFemale.jpg Swans, Geese, Ducks - Northern Pintail (f) (Copy) Northern Pintail (f) - Status: Uncommon to rare summer resident; fairly common migrant and winter resident. - Populations: Small numbers of Northern Pintails mix in with flocks of other dabblers on prairie ponds and reservoirs throughout eastern Colorado. They breed from northern Colorado north through much of Canada to Alaska. Nesting in Boulder County is poorly documented. They winter from British Columbia and New Mexico south to Central America. - Conservation: North American populations approached 10 million during the 1960s, then plummeted to 2-4 million during the drought years of the early 1990s. Numbers appear to be recovering. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143467349-P0STWV99UVZO44QGFAAT/GreenWingedTealMale.jpg Swans, Geese, Ducks - Green-winged Teal (m) (Copy) Green-winged Teal (m) - Status: Uncommon summer resident; fairly common migrant and winter resident. - Populations: These compact, colorful dabblers nest in river deltas and forest wetlands from Colorado north to central Canada and Alaska. In winter look for them in ice-free streams such as Boulder Creek and Clear Creek. - Conservation: Because most of their breeding areas are far from human activities, these exquisitely-marked teal have been able to maintain relatively high breeding populations of 3-5 million in North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143489132-FOFT67CZY2QES7NT7AYM/GreenWingedTealFemale.jpg Swans, Geese, Ducks - Green-winged Teal (f) (Copy) Green-winged Teal (f) - Status: Uncommon summer resident; fairly common migrant and winter resident. - Populations: These compact, colorful dabblers nest in river deltas and forest wetlands from Colorado north to central Canada and Alaska. In winter look for them in ice-free streams such as Boulder Creek and Clear Creek. - Conservation: Because most of their breeding areas are far from human activities, these exquisitely-marked teal have been able to maintain relatively high breeding populations of 3-5 million in North America. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143614580-YIYHPCDO3DS3BXP945C2/CanvasbackMale.jpg Swans, Geese, Ducks - Canvasback (m) (Copy) Canvasback (m) - Status: Uncommon to fairly common migrant and winter resident. - Populations: Modest numbers of canvasbacks mix in with flocks of redheads, lesser scaup, and ring-necked ducks, especially during fall and winter. Look for them at Walden Ponds, Valmont Reservoir, and Presbyterian Pond (northeast corner of Valmont and 63rd). They nest from Wyoming north through the Prairie Pothole region to northern Canada and Alaska. Known as the "aristocrats of ducks," these large, elegant divers can reach pond bottoms 30 feet or more below the surface, where they root around for tubers and roots of succulent plants. - Conservation: Declining North American populations during the 1980s landed the species on the Audubon Society "Blue List" of threatened birds, but numbers have recovered since then and most nesting populations seem secure. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592143624336-IC9HDBFNPDVAIRHQH3KF/CanvasbackFemale.jpg Swans, Geese, Ducks - Canvasback (f) (Copy) Canvasback (f) - Status: Uncommon to fairly common migrant and winter resident. - Populations: Modest numbers of canvasbacks mix in with flocks of redheads, lesser scaup, and ring-necked ducks, especially during fall and winter. Look for them at Walden Ponds, Valmont Reservoir, and Presbyterian Pond (northeast corner of Valmont and 63rd). They nest from Wyoming north through the Prairie Pothole region to northern Canada and Alaska. Known as the "aristocrats of ducks," these large, elegant divers can reach pond bottoms 30 feet or more below the surface, where they root around for tubers and roots of succulent plants. - Conservation: Declining North American populations during the 1980s landed the species on the Audubon Society "Blue List" of threatened birds, but numbers have recovered since then and most nesting populations seem secure. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998545251-HCNHA1ZZTR91OCKICK8S/redheadduck1.jpg Swans, Geese, Ducks - Redhead Duck (m) (Copy) Redhead Duck (m) - Status: Uncommon summer resident; abundant to fairly common migrant and winter resident. - Populations: Redheads appear by the thousands on prairie lakes and reservoirs throughout eastern Boulder County in October-November and February-March. Walden Ponds and Union Reservoir are particularly good places to see them. They breed primarily in the Prairie Pothole region of the northern plains, but breeding populations also concentrate in California's Central Valley as well as areas of North Texas and Alaska. Breeding has not been documented in Boulder County. - Conservation: Redheads practice "facultative brood parasitism," often laying some or all their eggs in nests of other species. From 1955-2005, North American breeding numbers ranged from 300,000-1,000,000, with no apparent long-range upward or downward trends. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998622932-O4WJP9IMO2SDE8GL2MT4/ringneckedduck1.jpg Swans, Geese, Ducks - Ring-necked Duck (m) (Copy) Ring-necked Duck (m) - Status: Common migrant; fairly common winter resident; uncommon summer resident. - Populations: Small numbers nest on the shores of mountain ponds surrounded by willow thickets west of the Peak-to-Peak Highway. Long Lake, west of Brainerd Lake, is a good place to see them. Thousands of migrants gather in fall and early spring at prairie lakes and reservoirs, including Sawhill and Walden Ponds, Somberero Marsh, and Pella Crossing. - Conservation: Because nesting pairs require undisturbed willow thickets and ponds, ring-necked ducks are listed as "isolated and restricted" on the Boulder County Birds of Special Concern list. Nesting populations appear to have remained fairly stable since 1980. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998689740-0661FZGQB6NP6VVMNSVN/ringneckedduck2.jpg Swans, Geese, Ducks - Ring-necked Duck (f) (Copy) Ring-necked Duck (f) - Status: Common migrant; fairly common winter resident; uncommon summer resident. - Populations: Small numbers nest on the shores of mountain ponds surrounded by willow thickets west of the Peak-to-Peak Highway. Long Lake, west of Brainerd Lake, is a good place to see them. Thousands of migrants gather in fall and early spring at prairie lakes and reservoirs, including Sawhill and Walden Ponds, Somberero Marsh, and Pella Crossing. - Conservation: Because nesting pairs require undisturbed willow thickets and ponds, ring-necked ducks are listed as "isolated and restricted" on the Boulder County Birds of Special Concern list. Nesting populations appear to have remained fairly stable since 1980. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998780691-INFBLPAK6X8UP0TCR2RX/greaterscaup1.jpg Swans, Geese, Ducks - Greater Scaup (m) (Copy) Greater Scaup (m) - Status: Rare migrant and winter resident. - Populations: A few individuals mix with flocks of other diving ducks on ponds and reservoirs on the plains from November-April. Note the rounded head of males (Lesser Scaup has a subtle notch near the top), with green sheen. Nests in coastal tundra areas of the North American and Siberian Arctic. - Conservation: North American breeding populations number slightly more than a half-million. Global warming may threaten viability of some northern nesting areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591998806240-X9ZSSKNHSTZ07DPNMCCM/greaterscaup3.jpg Swans, Geese, Ducks - Greater Scaup (f) (Copy) Greater Scaup (f) - Status: Rare migrant and winter resident. - Populations: A few individuals mix with flocks of other diving ducks on ponds and reservoirs on the plains from November-April. Note the rounded head of males (Lesser Scaup has a subtle notch near the top), with green sheen. Nests in coastal tundra areas of the North American and Siberian Arctic. - Conservation: North American breeding populations number slightly more than a half-million. Global warming may threaten viability of some northern nesting areas. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591999017159-JH3VFFJWPF7VHDPATP76/LesserScaup1.jpg Swans, Geese, Ducks - Lesser Scaup (m) (Copy) Lesser Scaup (m) - Status: Fairly common migrant and winter resident. - Populations: Look for Lesser Scaups mixed in with flocks of Redheads and Ring-Necked ducks at Walden Ponds, Valmont Reservoir, and Union Reservoir. Millions nest in boreal forests and parklands from Manitoba north and west to central Alaska. Note the slightly notched head of males and purple sheen on the sides of the head. - Conservation: Between 4 million and 8 million individuals were counted annually during 1955-95, making this the most abundant diving duck in North America. Continental populations may have declined recently. Loss of prairie potholes and poisoning from contaminated prey, including zebra mussels, may threaten some populations. Photo © 2013, Stephen Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1591999055128-K1YFPYG0N4JOIJT4JSTX/LesserScaup2.jpg Swans, Geese, Ducks - Lesser Scaup (f) (Copy) Lesser Scaup (f) - Status: Fairly common migrant and winter resident. - Populations: Look for Lesser Scaups mixed in with flocks of Redheads and Ring-Necked ducks at Walden Ponds, Valmont Reservoir, and Union Reservoir. Millions nest in boreal forests and parklands from Manitoba north and west to central Alaska. Note the slightly notched head of males and purple sheen on the sides of the head. - Conservation: Between 4 million and 8 million individuals were counted annually during 1955-95, making this the most abundant diving duck in North America. Continental populations may have declined recently. Loss of prairie potholes and poisoning from contaminated prey, including zebra mussels, may threaten some populations. Photo © 2013, Stephen Jones https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000331157-7BWN4Y8ICQZVL63HZ98N/surfscoter1.jpg Swans, Geese, Ducks - Surf Scoter (Copy) Surf Scoter Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000643256-9CK8VFO5ZVUFJ2MOMZ32/longtailedduck3.jpg Swans, Geese, Ducks - Long-tailed Duck (Copy) Long-tailed Duck Photo © 2014, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000930138-TJPDB2F99AQZMTVXP4PA/bufflehead1.jpg Swans, Geese, Ducks - Buffelhead (m) (Copy) Buffelhead (m) Bufflehead (m)Item 35 of 261 - Status: Fairly common migrant and winter resident. - Populations: These expert divers frequent gravel ponds and large reservoirs throughout eastern Boulder County from October-May. They nest in tree cavities in boreal forests and aspen parklands of northern Canada and Alaska. - Conservation: Numbers increased markedly from the 1950s to the 1990s, when the North American population exceeded 1 million. Hunters take a substantial toll on migrating flocks. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592000974479-VMROX04QEFG8TP8IFR49/bufflehead2.jpg Swans, Geese, Ducks - Buffelhead (f) (Copy) Buffelhead (f) Bufflehead (m)Item 35 of 261 - Status: Fairly common migrant and winter resident. - Populations: These expert divers frequent gravel ponds and large reservoirs throughout eastern Boulder County from October-May. They nest in tree cavities in boreal forests and aspen parklands of northern Canada and Alaska. - Conservation: Numbers increased markedly from the 1950s to the 1990s, when the North American population exceeded 1 million. Hunters take a substantial toll on migrating flocks. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001098101-ZJFTQVBTSH6A2R3RR713/commongoldeneye2.jpg Swans, Geese, Ducks - Common Goldeneye (m) (Copy) Common Goldeneye (m) - Status: Fairly common winter resident; uncommon migrant - Populations: These flashy divers frequent reservoirs and gravel ponds throughout Boulder County, especially during the winter months. They nest in tree cavities in boreal forests and aspen groves throughout most of Canada. Note the oblong (as opposed to crescent-shaped) white spot between the eye and the bill of the male. - Conservation: North American populations appear to be stable, though some nesting areas may be threatened by acidification, deforestation, and removal of potential nesting trees. Hunters kill 60,000-200,000 each winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001143617-UKGGXU52CH6Z8G51GFPZ/commongoldeneye1.jpg Swans, Geese, Ducks - Common Goldeneye (f) (Copy) Common Goldeneye (f) - Status: Fairly common winter resident; uncommon migrant - Populations: These flashy divers frequent reservoirs and gravel ponds throughout Boulder County, especially during the winter months. They nest in tree cavities in boreal forests and aspen groves throughout most of Canada. Note the oblong (as opposed to crescent-shaped) white spot between the eye and the bill of the male. - Conservation: North American populations appear to be stable, though some nesting areas may be threatened by acidification, deforestation, and removal of potential nesting trees. Hunters kill 60,000-200,000 each winter. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001273906-N5GWJEU2DAWN5B2BY14D/BarrowsGoldeneyeMale.jpg Swans, Geese, Ducks - Barrow's Goldeneye (m) (Copy) Barrow's Goldeneye (m) (Boulder County Extirpated Nesting Populations) - Status: Rare migrant and winter resident. Extirpated nesting species in Boulder County. - Populations: A few wanderers are seen on gravel ponds and reservoirs November-April. Several pairs nest in tree cavities in the Flattops Wilderness, and Denis Gale observed nesting within the Boulder watershed, west of Ward, during the 1880s. Boulder County is at the southern tip of their North American breeding range, which extends up the spine of the Rockies through Canada and into Alaska. - Conservation: Nesting pairs could become reestablished locally if fires or beaver activity created more suitable nesting trees bordering subalpine lakes. About 200,000 individuals inhabit North America, half of them in a single Canadian province. Populations appear to be relatively stable. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001321521-F4E40CZB7AOWJKS0YL14/BarrowsGoldeneyeFemale.jpg Swans, Geese, Ducks - Barrow's Goldeneye (f) (Copy) Barrow's Goldeneye (f) (Boulder County Extirpated Nesting Populations) - Status: Rare migrant and winter resident. Extirpated nesting species in Boulder County. - Populations: A few wanderers are seen on gravel ponds and reservoirs November-April. Several pairs nest in tree cavities in the Flattops Wilderness, and Denis Gale observed nesting within the Boulder watershed, west of Ward, during the 1880s. Boulder County is at the southern tip of their North American breeding range, which extends up the spine of the Rockies through Canada and into Alaska. - Conservation: Nesting pairs could become reestablished locally if fires or beaver activity created more suitable nesting trees bordering subalpine lakes. About 200,000 individuals inhabit North America, half of them in a single Canadian province. Populations appear to be relatively stable. Photo © 2013, Jennifer Price https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001430097-C88UFXQUF1KWWY4QKGSF/HoodedMerganserMale.jpg Swans, Geese, Ducks - Hooded Merganser (m) (Copy) Hooded Merganser (m) - Status: Fairly common migrant and winter resident. - Populations: Small groups winter on mid-sized gravel ponds and reservoirs throughout eastern Boulder County. Look for them at Presbyterian Pond (63rd and Valmont) in fall and spring, Baseline Reservoir in late fall, and Sawhill Ponds, fall and spring. As many as 100 may winter on Valmont Reservoir. These cavity-nesters breed in forested regions from the Mississippi River east to the Atlantic Seaboard and in the Northern Rockies and British Columbia. - Conservation: Though nesting pairs may be sensitive to deforestation and acid rain, populations appear to be stable or slightly increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001470932-VJ903LKKPVUAPHE8VDKJ/HoodedMerganserFemale.jpg Swans, Geese, Ducks - Hooded Merganser (f) (Copy) Hooded Merganser (f) - Status: Fairly common migrant and winter resident. - Populations: Small groups winter on mid-sized gravel ponds and reservoirs throughout eastern Boulder County. Look for them at Presbyterian Pond (63rd and Valmont) in fall and spring, Baseline Reservoir in late fall, and Sawhill Ponds, fall and spring. As many as 100 may winter on Valmont Reservoir. These cavity-nesters breed in forested regions from the Mississippi River east to the Atlantic Seaboard and in the Northern Rockies and British Columbia. - Conservation: Though nesting pairs may be sensitive to deforestation and acid rain, populations appear to be stable or slightly increasing. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001595977-MM1AJALJA6AS5ZQYSDTS/CommonMerganserMale.jpg Swans, Geese, Ducks - Common Merganser (m) (Copy) Common Merganser (m) - Status: Uncommon summer resident; common winter resident. - Populations: Large flocks cruise across Baseline Reservoir, Valmont Reservoir, Union Reservoir, and other large bodies of water on the plains, November-April. A few pairs nest in tree cavities or nest boxes on shorelines of gravel pits near Lyons. Colorado is at the southern tip of the North American breeding range, which extends up into Alaska and across forested regions of northern Canada to Labrador. - Conservation: These fish-eaters are particularly vulnerable to pesticides and other contaminants. North American population status is unknown. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001607375-QQR3DNBCJOUM6KDU28D5/CommonMerganserFemale.jpg Swans, Geese, Ducks - Common Merganser (f) (Copy) Common Merganser (f) - Status: Uncommon summer resident; common winter resident. - Populations: Large flocks cruise across Baseline Reservoir, Valmont Reservoir, Union Reservoir, and other large bodies of water on the plains, November-April. A few pairs nest in tree cavities or nest boxes on shorelines of gravel pits near Lyons. Colorado is at the southern tip of the North American breeding range, which extends up into Alaska and across forested regions of northern Canada to Labrador. - Conservation: These fish-eaters are particularly vulnerable to pesticides and other contaminants. North American population status is unknown. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001703934-OBEQQ38NZQ6LKRYTWSQB/RedBreastedMerganser.jpg Swans, Geese, Ducks - Red-breasted Merganser (Copy) Red-breasted Merganser - Status: Fairly common migrant and winter resident. - Populations: Look for small and scattered flocks mixed in with larger flocks of Common Mergansers on Valmont Reservoir, Baseline Reservoir, and Union Reservoir, October-April. These ground-nesting mergansers breed in northern boreal forests and the Arctic tundra from Alaska clear across the continent to Labrador, Baffin Island, and Greenland. - Conservation: While numbers declined steeply during the first two-thirds of the twentieth century, they appear to have recovered somewhat during the past two decades. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001803572-HJ7VRIYIHAM2DUYO56PP/RuddyDuckMale.jpg Swans, Geese, Ducks - Ruddy Duck (m) (Copy) Ruddy Duck (m) - Status: Uncommon summer resident; fairly common migrant and rare winter resident. - Populations: Small numbers appear on Boulder County gravel ponds and reservoirs during spring and fall migration. Though some stay throughout the summer and pairs have nested throughout the plains and mountain parks of Colorado, nesting has not been clearly documented in Boulder County. Ruddy Ducks nest all the way from southern Mexico to northern Canada, especially in grassland areas, with the largest nesting concentrations occurring in the Prairie Pothole region. - Conservation: North American populations appear to be stable or increasing. Ruddy Ducks have been introduced to Europe, where they are disdained by hunters and considered a pest by others. Photo © 2013, Gerhard Assenmacher https://images.squarespace-cdn.com/content/v1/5e90a20af88c6a3135d7432c/1592001818144-KPTWSHBGNLJIBG9XV6A5/RuddyDuckFemale.jpg Swans, Geese, Ducks - Ruddy Duck (f) (Copy) Ruddy Duck (f) - Status: Uncommon summer resident; fairly common migrant and rare winter resident. - Populations: Small numbers appear on Boulder County gravel ponds and reservoirs during spring and fall migration. Though some stay throughout the summer and pairs have nested throughout the plains and mountain parks of Colorado, nesting has not been clearly documented in Boulder County. Ruddy Ducks nest all the way from southern Mexico to northern Canada, especially in grassland areas, with the largest nesting concentrations occurring in the Prairie Pothole region. - Conservation: North American populations appear to be stable or increasing. Ruddy Ducks have been introduced to Europe, where they are disdained by hunters and considered a pest by others. 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