Bronzed Cowbird

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Blackbirds

Bronzed CowbirdMolothrus aeneus

ORDER: Passeriformes
FAMILY: Icteridae

Basic Description

A compact, bull-necked bird of open country, the Bronzed Cowbird forages for seeds and grains on the ground, usually in flocks. In good light, the male shimmers with deep glossy blue on the wing and a black body with a velvety bronze sheen. Males and females have intense red eyes. Like their relatives, the smaller Brown-headed Cowbirds, these unusual birds are “brood parasites”—they lay their eggs in other birds’ nests, leaving the hosts to provide all the care for their young.

More ID Info

Year-roundBreedingMigrationNonbreeding

Range map provided by Birds of the World

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Find This Bird

Within their range in the southern U.S. and farther south, Bronzed Cowbirds are rather easy to find in open habitats like pastures, farm fields, golf courses, and scrubby grasslands—though they’re not as numerous as the similar Brown-headed Cowbird. Also look for them around spilled grain, in places such as grain elevators and feedlots. Bronzed Cowbirds often lay eggs in Hooded Oriole nests, so if you find Hooded Orioles be on the lookout for cowbirds. Normally, Bronzed Cowbirds travel and forage in small flocks, sometimes with other blackbird species.

Other Names

Tordo Ojirrojo (Spanish)
Vacher bronzé (French)

Cool Facts
- The Bronzed Cowbird expanded its range during the twentieth century, especially since the 1950s. As agriculture expanded in South Texas, Bronzed Cowbirds spread rapidly northward. The first record of Bronzed Cowbird from Louisiana came in 1961.
- Both Brown-headed and Bronzed Cowbirds have expanded their ranges recently, and the two species now overlap extensively. Competition for host nests has been one result. Bronzed Cowbirds tend to lay eggs in the nests of larger species than the Brown-headed does—but people have reported many host nests containing the eggs of both cowbird species.
- Many species of songbird that are regular hosts to Bronzed Cowbird eggs attack the cowbirds when they are near their nest, which suggests that they perceive the cowbird as a threat to the nest. Couch’s Kingbirds, Hooded Orioles, and Northern Mockingbirds are especially aggressive toward Bronzed Cowbirds.
- At least 101 species of songbirds have been known to host Bronzed Cowbird eggs in their nests. These range in size from the small Golden-cheeked Warbler to the sizeable Green Jay.
- Bronzed Cowbirds often parasitize the nests of orioles. Birders have noticed that the sound of an oriole singing in the springtime often brings in both male and female Bronzed Cowbirds.
- The record for the number of Bronzed Cowbird eggs found in a single nest is 17.
- The oldest recorded Bronzed Cowbird was a male, and at least 8 years old when he was found in Texas.