The brown-headed cowbird is a small, stocky, round, black bird, which can be observed by its short tail and thick head in relation to its body. The bill is also short and thick, that helps it in foraging. 

The males and females look different, with the males being larger and heavier. The male brown-headed cowbird has a brown coloring to its head, with black, glossy-looking feathers on its body. In certain lights, the brown head can look black as well. The female brown-headed cowbird will lack any black coloring and look plain brown with light coloring on the head and underside.

Brown-headed cowbirds can be found throughout the United States, most of Canada, and northern Mexico. Depending on where the population is, they can migrate within their range to breeding and wintering sites. 

Brown-headed cowbirds favor an abundance of habitats, particularly forest edges of prairies, open fields, and grasslands. In the breeding season, they favor open agricultural farmlands that make foraging easier. Fragmentation of forested lands due to human development has proved helpful in maintaining this bird’s habitat.

The brown-headed cowbird will often find its food on the ground, which is why open fields prove beneficial to this species. They are herbivores and eat a variety of food found on the ground, including seeds and insects.

Brown-headed cowbirds will forage in fields with cattle, and the movement of the cattle in the pasture will disturb the insects on the ground. When these insects are disturbed, they will become flushed out from the ground and become easier for the brown-headed cowbirds to eat.

The brown-headed cowbird is a brood parasite, meaning they do not make their own nests, but lay their eggs in the nests of other species and rely on the different birds to raise the young cowbird.

Brown-headed cowbirds have many different mates in a breeding season, and each clutch will have anywhere from 1-7 eggs. The young birds develop rapidly and will leave the host nest after 10 days of hatching. The brown-headed cowbird eggs are often white and gray in coloring with distinct brown markings on the eggs.

The brown-headed cowbird is known to lay eggs in over 140 different species’ nests, ranging from small kinglet birds to large meadowlarks. Before the brown-headed cowbird lays an egg, it will remove one of the host species’ eggs. Some birds have evolved mechanisms to detect and reject cowbird eggs in their nest. 

The name “cowbird” comes from the association they used to have with cows and horses that inhabit pastures and, therefore, create foraging opportunities for cowbirds.

The call of the brown-headed cowbird sounds similar to that of a water faucet dripping.