Some come in flocks. Some come in droves. And some come in murders.
Brown-headed cowbirds are robin-sized black birds whose range covers most of North America. From a people’s point of view cowbirds are what we might call deadbeat parents. Cowbirds lay their eggs in the nests of other bird species, and the cowbird nestlings are raised by the foster parents. Since the cowbirds spend their formative months with birds of an entirely different species which has separate habits, songs, etc., how does a cowbird know it’s a cowbird? Learn more on this Moment of Science.