The Bronzed Cowbird is a mostly dark blackbird with a thick bill and curved upper mandible. Adults have red eyes.
Males have mostly black plumage with glossy bluish wings. A thick ruff of feathers on the neck creates a humpbacked appearance.
FemaleEastern females are fairly uniform brownish-black in color. Western females are a much paler grayish-brown color.
Seasonal change in appearanceNone.
JuvenileJuveniles are similar to winter females, but are faintly streaked below.
HabitatBronzed Cowbirds inhabit open country, feedlots, and brushy areas.
DietBronzed Cowbirds eat insects and seeds.
BehaviorBronzed Cowbirds forage on the ground in open areas.
RangeBronzed Cowbirds breed in the southwestern U.S. They winter in Mexico. The population is stable after a large expansion decades ago.
Two U.S. subspecies account for the plumage differences in eastern and western birds; two additional subspecies do not occur in the U.S.
Bronzed Cowbird parasitism has impacted Hooded Oriole populations in Texas.
VocalizationsThe song consists of a soft whistle bracketed by gurgles. Whistle or rattle calls are given as well.
The Bronzed Cowbird builds no nest, instead laying its eggs in the nests of other birds.
Bronzed Cowbirds can lay dozens of eggs over the course of a breeding season. They are pale blue-green in color.
Incubation and fledging: