Brown-headed Cowbird

On 10 May 2016, I photographed a male (above) and female (below) Brown-headed Cowbirds. Cowbirds are brood parasites. They lay their eggs in other birds’ nests. Over 220 host species have been cataloged. The pressure on the hosts a be substantial. Female cowbirds can lay up to 40 eggs per season and the cowbirds wander widely (Lowther 1993).

Cowbirds were originally found only in short-grass prairies, They ate insects disturbed by bison herds. With the ecological agricultural and urban homogenization of North America, Brown-headed Cowbirds are now found from coast to coast in southern Canada, the United States and Mexico.