Facts about Brown-headed Cowbird

1. 08

   The brown-headed cowbird historically followed bison herds across the Great Plains, a nomadic lifestyle that drove the evolution of its brood parasitism.

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2. 07

   Young brown-headed cowbirds recognize and respond to species-specific calls from their own kind within days of fledging, despite being raised entirely by foster parents of different species.

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3. 06

   Cowbird chicks fledge from host nests within 8-10 days, earlier than most host species, giving them a developmental advantage in competition for parental care.

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4. 05

   Across North America, brown-headed cowbirds parasitize over 220 different host bird species, from warblers to sparrows to thrushes.

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5. 04

   Brown-headed cowbirds have expanded their range northward by approximately 1,000 kilometers since the 1800s due to deforestation creating suitable grassland habitat.

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6. 03

   Nestling brown-headed cowbirds grow approximately 40 percent faster than host chicks, outcompeting them for food and often causing their starvation.

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7. 02

   Male brown-headed cowbirds perform a distinctive display involving wing-drops and vocalizations to attract mates during breeding season.

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8. 01

   Female brown-headed cowbirds lay approximately 36 eggs per breeding season across multiple host nests, making them prolific brood parasites.

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