Brown-headed Cowbird

Molothrus ater

Brown-headed Cowbird, Molothrus ater, photo © by Robert Shantz

This Brown-headed Cowbird (male), was photographed by Robert Shantz at Duncan, Arizona.

In the Sonoran Desert the Brown-headed Cowbird is common in city and riparian habitats, and occasionally well into desert environs. These birds breed during summer and are brood parasites, i.e. they put their eggs in other bird species' nests. Warblers and sparrows are frequent hosts. During the autumn-winter non-breeding season they are partial to agricultural fields and often follow grazing animals catching insects stirred up by the movements. They also feed on grain at feedlot operations and in freshly harvested fields. Cowbird abundance is enhanced by human activities and thus the pressure they put on the breeding success of their hosts.

Year-round Resident - Partial Migration - more common in winter

Brown-headed Cowbird, Molothrus ater, © Michael Plagens

Male Brown-headed Cowbird from Phoenix, Arizona. 10 June 2012.

More Information:

Sonoran Desert Field Guide
Sonoran Desert Places
Sonoran Desert Naturalist Home Page


Copyright Michael J. Plagens, page created 30 Aug. 2006,
updated 25 July 2022.