Brown-headed Cowbird

Overview

The brown-headed cowbird (Molothrus ater) is a small, obligate brood parasitic icterid native to temperate and subtropical North America. It is a permanent resident in the southern parts of its range, while northern populations migrate to the southern United States and Mexico for winter. This species is classified as Least Concern on the IUCN Red List.

Identification

• Adult males are iridescent black with a brown head, while females are slightly smaller, dull grey with a pale throat and fine streaking on the underparts.
• Distinguished by its finch-like head and beak within the icterid shape.
• Total length ranges from 16–22 cm with an average wingspan of 36 cm; body mass ranges from 30–60 g, with males averaging 49 g and females 38.8 g.

Habitat

The species inhabits open or semiopen country and often travels in flocks, sometimes mixing with red-winged blackbirds, bobolinks, common grackles, or European starlings. It is commonly seen following grazing animals such as horses and cattle, and is now frequently found at suburban birdfeeders.

Diet

Foraging primarily on the ground, often following larger grazing animals to catch insects stirred up by their movement. The diet consists mainly of seeds and insects, with rare consumption of berries.

Did you know?

Females can lay up to 40 eggs in a single season, and they exhibit 'mafia behavior' by ransacking nests if their eggs are removed to prevent host species from abandoning the parasitised nest.