Brown-headed Cowbird

The Brown-headed Cowbird (Molothrus ater), is the most common of three different cowbird species in the United States.

The male in the picture on the left shows the bird's characteristic brown head on a uniformly dark body. The picture below shows the more uniformaly brown colored female.

Icterid Species Grackle Meadowlark Brewer's Blackbird Yellow-headed Blackbird Red-winged Blackbird Bullock's Oriole Hooded Oriole Types of Birds

Cowbirds are known as brood parasites because pairs move about their range during breeding season in order for the female to lay eggs in host bird nests. Because of the female's ability to produce multiple broods/season, cowbird populations remain stable despite the occasional natural intrusions or poor parenting that might beset any one or two of the total number of nests they parasitize during the season.

There is some research examining the effects that cowbird breeding practices have on host populations. Despite any definitive conclusions about the relationship, communities across the United States continue to call for cowbird management plans.

Like other icterids, cowbirds feed on both insects and seeds, with seeds the food of choice in non-breedng season. Most cowbirds migrate short to medium distances between winter resting and summer breeding grounds.

© 2005-2007 Patricia A. Michaels