Brown-headed Cowbird


Common Name:Brown-headed Cowbird





Molothrus ater

Photo: Ivan Andrijevic



The Brown-headed Cowbird is a blackbird. They look very similar to the Common Grackle in that they have a glossy blue-black body. However, the Brown-headed Cowbird is distinguished by its dark brown head and neck contrasting with his blackish body. Like other blackbirds, the Brown-headed Cowbird is dichromatic, meaning the male and female look different. The female is a plain gray-brown, and could be confused for a large female sparrow.  Cowbirds have a short, finch-like bill, very different from the longer bill of the Common Grackle. They are 17-22 cm (7-9 in)  in size with a 28-36 cm (11-14 in) wingspan. They weigh 38-50 g (1.34-1.77 ounces).

Photo: M. Noonan


The Brown-headed Cowbird is found throughout the United States. They are found year-round in Northern Mexico and the states east of Texas and Iowa, and during the breeding season they can be found from California and up into Alberta and British Columbia. The Brown-headed Cowbird is usually found in areas with grassland and low or scattered trees, such as woodland edges, brushy thickets, fields, prairies, pastures, orchards, and residential areas. Cowbirds mainly eat seeds and grains, but also are known to dine on arthropods such as grasshoppers and beetles. The Cowbird forages on ground, often in association with cows or horses (which is where their name is derived from). Cowbirds often follow walking cattle that will disturb insects on the ground and give the Cowbird an easy meal.


Photos: Melissa Grippin




The Brown-headed Cowbird is a brood parasite, meaning the female does not make a nest of her own, but lays her eggs in the nests of many different species. These unsuspecting birds then raise the young cowbirds. Studies have been shown that Cowbirds do not prefer the nest or parent methods of a certain bird. In fact, it has been found that over 220 species have been parasitized by the Cowbird! The Cowbird egg is usually white or grayish with brown or gray spots. Because the Cowbird does not care for her own eggs, it is hard to tell the incubation period of the eggs, but it is most likely between 10-14 days. The young fledge between 8-13 days after hatching.




Brown-headed Cowbird is most likely to be found in places that have mostly short, open grasses and scattered trees. They are mostly found in urban areas, parks and along side roads and are found in WNY all year round but are most common during the summer.


Birds of Western New York is brought to you by the Institute for the Study of Human-Animal Relations at Canisius College in Buffalo, NY.