BRONZED COWBIRD

(Molothrus aeneus)

eBird gives this description of the Bronzed Cowbird:  Dark brown to matte black; males with iridescent bluish wings. Thick neck and heavy bill. Look for vampire-like staring red eye. Males have an incredible display where they puff out a mane of neck feathers and hover in a circle above the female. Found in a variety of open or semi-open areas, including pastures, forest edge, yards, and agricultural areas. Visits feeders. Often in flocks, sometimes with other blackbirds.  All About Birds provides this additional descriptive information about the Bronzed Cowbird:  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.

I saw my first Bronzed Cowbird on the morning of June 22, 2020, at Sabal Palms Sanctuary, south of Brownsville, Texas.  That red eye is a stunner!

Bronzed Cowbird at Sabal Palms Sanctuary, June 22, 2020.


“Cool Facts” About The Bronzed Cowbird From All About Birds…

  • 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.