Brown-Headed Cowbird
Molothrus ater
Cowbirds are well known as nest, or brood parasites. Some theorists believe that Brown-Headed Cowbirds developed this practice when they followed the great bison herds migrating from present day Mexico to Canada. To keep up with the migration, these birds would deposit their eggs in other bird’s nests, depending on their victims to raise the cowbird’s young. Cowbird chicks develop much faster than that of their hosts, so the host’s offspring rarely survive. Some host species learned to abandon an infected egg clutch and start a fresh one on top of the one with cowbird eggs. Other species have not done so well, resulting in populations declines.
Modern science recognises four subspecies of Brown-Headed Cowbird:
- M. a. artemisiae breeds in the interior of western Canada.
- M. a. obscurus breeds in coastal Alaska.
- M. a. ater breeds in southeast Canada and eastern and central USA.
- M. a. californicus breeds in southern California and northern Baja California (Mexico).
Brown-Headed Cowbirds range over most of the North American continent, migrating north as far as southern and western Canada in summer. Many of these birds remain year-round on the west coast, and southwestern USA. They also stay in northern Mexico, Texas and through the lower Mississippi Valley. And they range to New England and southeastern USA to northern Florida. South Florida and southern Mexico normally see them only in winter.
It is easy to dislike cowbirds if we apply human values to their practices. When I have met them during my travels in the western USA, I try to remember that nature can be harsh. My value system is irrelevant in the larger scheme of the natural world.
35 Photos
Brown-Headed Cowbird(Molothrus ater) |
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Description: Female along Rockhouse Truck Trail near Clark Lake in the Anza Borrego State Park. San Diego County, California. |
Date Taken: 2013:04:27 7:49 |
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Location:
Rockhouse Trail |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/1000 |
File Name: D3X5100-BrownHeadedCowBird |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Male along Rockhouse Truck Trail near Clark Lake in the Anza Borrego State Park. San Diego County, California. |
Date Taken: 2013:04:27 7:49 |
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Location:
Rockhouse Trail |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/400 |
File Name: D3X5108-BrownHeadedCowBird |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Male along Rockhouse Truck Trail near Clark Lake in the Anza Borrego State Park. San Diego County, California. |
Date Taken: 2013:04:27 7:52 |
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Location:
Rockhouse Trail |
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Camera Information: NIKON D3X, 800 mm, f/6.3, 1/2500 |
File Name: D3X5139-BrownHeadedCowBird |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Female along Rockhouse Truck Trail near Clark Lake in the Anza Borrego State Park. San Diego County, California. |
Date Taken: 2013:04:27 7:54 |
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Location:
Rockhouse Trail |
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Camera Information: NIKON D3X, 800 mm, f/6.3, 1/2000 |
File Name: D3X5147-BrownHeadedCowBird |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: This feedlot in Red Rock Arizona has hosted some rare doves and sometimes other birds. Pinal County Arizona USA 2008-11-29. |
Date Taken: 2008:11:29 13:13 |
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Location:
Red Rock Feed Lot |
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Camera Information: NIKON D2X, 800 mm, f/6.3, 1/350 |
File Name: jcd3049BrownHeadedCowBird |
| © 2008 Jack Daynes, shadeTreeImaging.com |
Brown-headed Cowbird(Molothrus ater) |
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Description: Juvenile bird at a Dairy Farm, Valley Center, San Diego County, California. |
Date Taken: 2004:10:13 12:46 |
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Camera Information: NIKON D1X, 800 mm, f/11.0, 1/500 |
File Name: JCD_1081BrownHeadedCowbird |
| © 2004 Jack Daynes, shadeTree Imaging |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Bear River Migratory Bird Refuge, 17 miles west of Brigham City Utah. |
Date Taken: 2015:05:12 10:27 |
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Location:
Bear River Managment Area |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/1000 |
File Name: D3X1880-BrownHeadedCowBird |
| © 2015 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Bear River Migratory Bird Refuge, 17 miles west of Brigham City Utah. |
Date Taken: 2015:05:12 10:42 |
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Location:
Bear River Managment Area |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/3200 |
File Name: D3X1951-BrownHeadedCowBird |
| © 2015 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Where feeders are in place at the Visitor Center, local critters can be readily observed. Malheur NWR Headquarters in eastern Oregon. |
Date Taken: 2015:06:02 17:44 |
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Location:
Visitor Center |
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Camera Information: NIKON D3X, 800 mm, f/7.1, 1/1600 |
File Name: D3X7008-BrownHeadedCowBird |
| © 2015 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: This Brown-Headed Cowbird male was looking to find a female so his genes would contribute to next generation of nest parasites. I drove for three plus hours to spend two lovely hours with these birds at the Cienega in Arivaca before turning onto my final leg of my homeward journey from my 2020 Texas adventure. |
Date Taken: 2020:05:27 9:29 |
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Location:
Arivaca Cienega |
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Camera Information: NIKON D5, 800 mm, f/8.0, 1/8000 |
File Name: BrownHeadedCowbird_D5X6330-Arivaca |
| © 2020 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Yard birds in Aspendell are different than most folk's yard birds, but most folks don't have yards at over 8400 feet in the Eastern Sierras. Near Bishop California in Inyo County. |
Date Taken: 2017:07:19 11:08 |
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Location:
Aspendell |
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Camera Information: NIKON D5, 800 mm, f/8.0, 1/800 |
File Name: BrownHeadedCowBird_D5X0151-Aspendell |
| © 2017 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Rockhouse Truck Trail near Clark Lake in the Anza Borrego State Park. San Diego County, California. |
Date Taken: 2013:04:27 7:26 |
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Location:
Rockhouse Trail |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/2000 |
File Name: D3X5041-BrownHeadedCowBird |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: These critters can be readily observerd at the Malheur NWR Headquarters in eastern Oregon. |
Date Taken: 2015:06:02 18:06 |
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Location:
Malheur NWR |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/800 |
File Name: D3X7024-BrownHeadedCowbird |
| © 2015 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Near Oh Ridge Road at the north end of June Lake in California. |
Date Taken: 2016:05:08 16:47 |
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Location:
June Lake |
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Camera Information: NIKON D7200, 800 mm, f/8.0, 1/1250 |
File Name: D72-1805-BrownHeadedCowBird |
| © 2016 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: In close company with a group of Yellow-Headed Blackbirds at Dirty Socks Spring at the southern edge of the Owens Lake Basin, between Lone Pine and Olancha. |
Date Taken: 2016:04:20 17:36 |
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Location:
Dirty Socks Spring |
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Camera Information: NIKON D7200, 800 mm, f/8.0, 1/1250 |
File Name: D728068-BrownHeadedCowBird |
| © 2016 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Near the feed lot outside of Red Rock, Arizona 2013-08-29. |
Date Taken: 2013:08:29 15:27 |
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Location:
Red Rock |
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Camera Information: NIKON D3X, 800 mm, f/8.0, 1/1000 |
File Name: D3X2525-BrownHeadedCowBird-Juvenile |
| © 2013 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Cowbirds and blackbirds forage together on the lawn. I had an exceptional day at the SPI Convention Centre. I met three new bird species: Veery, Dickcissel, and Black-Billed Cuckoo. |
Date Taken: 2021:04:15 10:27 |
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Location:
Convention Center |
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Camera Information: NIKON D5, 800 mm, f/8.0, 1/1000 |
File Name: BrownHeadedCowbird_D5X5297-SPI_ConventionCtr |
| © 2021 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Cowbirds and blackbirds forage together on the lawn. I had an exceptional day at the SPI Convention Centre. I met three new bird species: Veery, Dickcissel, and Black-Billed Cuckoo. |
Date Taken: 2021:04:15 10:26 |
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Location:
Convention Center |
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Camera Information: NIKON D5, 800 mm, f/8.0, 1/1500 |
File Name: BrownHeadedCowbird_D5X5293-SPI_ConventionCtr |
| © 2021 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: By Flat Rock near the sea-wall that shelters the Crescent City harbor from the wrath of stormy seas, I found a mixed flock of blackbirds posing nicely. |
Date Taken: 2022:03:13 8:57 |
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Location:
Flat Rock |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/800 |
File Name: BrownHeadedCowbird_8506026-CrescentCity-FlatRock |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: The snow and frozen rain made traveling hazardous, so I found a large empty lot to park on the outskirts of Lewistown Montana. I planned to work on my blogs, but when I noticed four species of sparrows and other birds nearby, I had to grab my camera. |
Date Taken: 2022:05:20 12:08 |
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Location:
Stockyards |
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Camera Information: NIKON D850, 800 mm, f/9.0, 1/2500 |
File Name: BrownHeadedCowbird_8502376-Lewiston.MT_ |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: During my visit to Charlie Lake, north of Saint John British Columbia, I hoped I might meet Rusty Blackbirds. I had to settle for Brown-Headed Cowbirds. |
Date Taken: 2022:06:03 10:26 |
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Location:
Charlie Lake |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/6400 |
File Name: BrownHeadedCowbird_8506562-CharlieLake.BC_ |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Brown-Headed Cowbirds migrated to this region to lay their eggs in the nests of other species. I spent five nights at Grasslands National Park in southern Saskatchewan to complete my two-month tour of Canada in the spring of 2022. |
Date Taken: 2022:07:14 8:59 |
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Location:
Grasslands National Park |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/8000 |
File Name: BrownHeadedCowbird_8501096-Grasslands.NP-SK |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Brown-Headed Cowbirds migrated to this region to lay their eggs in the nests of other species. I spent five nights at Grasslands National Park in southern Saskatchewan to complete my two-month tour of Canada in the spring of 2022. |
Date Taken: 2022:07:14 9:00 |
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Location:
Grasslands National Park |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/8000 |
File Name: BrownHeadedCowbird_8501108-Grasslands.NP-SK |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Brown-Headed Cowbirds migrated to this region to lay their eggs in the nests of other species. I spent five nights at Grasslands National Park in southern Saskatchewan to complete my two-month tour of Canada in the spring of 2022. |
Date Taken: 2022:07:14 9:00 |
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Location:
Grasslands National Park |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/8000 |
File Name: BrownHeadedCowbird_8501118-Grasslands.NP-SK |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Brown-Headed Cowbirds migrated to this region to lay their eggs in the nests of other species. I spent five nights at Grasslands National Park in southern Saskatchewan to complete my two-month tour of Canada in the spring of 2022. |
Date Taken: 2022:07:14 9:02 |
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Location:
Grasslands National Park |
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Camera Information: NIKON D850, 800 mm, f/8.0, 1/8000 |
File Name: BrownHeadedCowbird_8501145-Grasslands.NP-SK |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: Brown-Headed Cowbirds migrated to this region to lay their eggs in the nests of other species. I spent five nights at Grasslands National Park in southern Saskatchewan to complete my two-month tour of Canada in the spring of 2022. |
Date Taken: 2022:07:14 9:57 |
|
Location:
Grasslands National Park |
|
Camera Information: NIKON D850, 800 mm, f/8.0, 1/6400 |
File Name: BrownHeadedCowbird_8501418-Grasslands.NP-SK |
| © 2022 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Near Oh Ridge Road at the north end of June Lake in California. |
Date Taken: 2016:05:08 16:46 |
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Location:
June Lake |
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Camera Information: NIKON D7200, 800 mm, f/8.0, 1/1250 |
File Name: D72-1804-BrownHeadedCowBird |
| © 2016 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: I spent the day south of Lawrence Kansas exploring the Baker Wetlands. Bird migration seemed in full swing, and I enjoyed every minute. |
Date Taken: 2023:04:27 10:23 |
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Location:
Baker Wetlands |
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Camera Information: NIKON Z 9, 800 mm, f/8.0, 1/800 |
File Name: BrownHeadedCowbird_ZX97604_BakerWetlands-KS |
| © 2023 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: I spent the day south of Lawrence Kansas exploring the Baker Wetlands. Bird migration seemed in full swing, and I enjoyed every minute. |
Date Taken: 2023:04:27 10:42 |
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Location:
Baker Wetlands |
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Camera Information: NIKON Z 9, 800 mm, f/8.0, 1/800 |
File Name: BrownHeadedCowbird_ZX97684_BakerWetlands-KS |
| © 2023 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: I spent the day meeting birds at Sky Meadows State Park in Virginia. It is a 1,862-acre park about an hour outside of the Washington, D.C. metro region, where there are meadows and forests stretching up to the ridge of the mountain and the Appalachian Trail. |
Date Taken: 2023:06:13 11:10 |
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Location:
Sky Meadows State Park |
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Camera Information: NIKON Z 9, 800 mm, f/10.0, 1/800 |
File Name: BrownHeadedCowbird_Z9X7236_SkyMeadows-SP-VA |
| © 2023 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: Before I settled in at my campsite at Davis Mountains State Park, I stopped at their “Wildlife Viewing Area”. The light wasn’t great, but the birds were pretty nice. |
Date Taken: 2023:07:04 15:23 |
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Location:
Davis Mountains State Park |
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Camera Information: NIKON Z 9, 800 mm, f/8.0, 1/800 |
File Name: BrownHeadedCowbird_Z9X9675_DavisMountains.SP-TX |
| © 2023 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
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Description: To start my visit to ‘tropical Texas’ in 2024, I first stopped by Laguna Atascosa on my way to South Padre Island. It rarely disappoints me. Long-Billed Thrashers were looking sharp, as always. |
Date Taken: 2024:04:14 13:09 |
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Location:
Laguna Atascosa NWR |
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Camera Information: NIKON D850, 800 mm, f/6.3, 1/2500 |
File Name: BrownHeadedCowbird_8508677_LagunaAtascosa-TX |
| © 2024 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: To start my visit to ‘tropical Texas’ in 2024, I first stopped by Laguna Atascosa on my way to South Padre Island. It rarely disappoints me. Long-Billed Thrashers were looking sharp, as always. |
Date Taken: 2024:04:14 13:09 |
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Location:
Laguna Atascosa NWR |
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Camera Information: NIKON D850, 800 mm, f/6.3, 1/3200 |
File Name: BrownHeadedCowbird_8508680_LagunaAtascosa-TX |
| © 2024 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: To start my visit to ‘tropical Texas’ in 2024, I first stopped by Laguna Atascosa on my way to South Padre Island. It rarely disappoints me. Long-Billed Thrashers were looking sharp, as always. |
Date Taken: 2024:04:14 13:14 |
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Location:
Laguna Atascosa NWR |
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Camera Information: NIKON D850, 800 mm, f/6.3, 1/1600 |
File Name: BrownHeadedCowbird_8508686_LagunaAtascosa-TX |
| © 2024 Jack Daynes, shadeTreeImaging.com |
Brown-Headed Cowbird(Molothrus ater) |
|
Description: The snow and frozen rain made traveling hazardous, so I found a large empty lot to park on the outskirts of Lewistown Montana. I planned to work on my blogs, but when I noticed four species of sparrows and other birds nearby, I had to grab my camera. |
Date Taken: 2022:05:20 12:07 |
|
Location:
Stockyards |
|
Camera Information: NIKON D850, 800 mm, f/9.0, 1/2500 |
File Name: BrownHeadedCowbird_8502361-Lewiston.MT_ |
| © 2022 Jack Daynes, shadeTreeImaging.com |
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