Brown-headed Cowbird

Brown-headed Cowbird

A parasitic nester, often found in mixed blackbird flocks or at feeders.  Once restricted to the Great Plains, now common in non-wooded areas across the US and Canada.  Usually on the ground in open habitats, or perched high on exposed tree branches.  Small for a blackbird, stocky, with a short, heavy bill; males are black with subtle brown hoods, and females are drabber brown; often cock tails.  Primarily seed eaters with some insects in diet.  Non-monogamous, and non-nest building: females lay eggs in other bird’s nests where they are raised by their hosts (up to 3 dozen eggs each season).  Young hatch early and may smother or push out host eggs or young.   This unusual nesting behavior may be related to their original relationship with traveling bison flocks, which prevented cowbirds from building and attending nests and young.  Lifespan up to 16 years.  Population ~ 120 million and slightly declining.   


Posted on

January 2, 2015