This rare video shows a female cowbird killing live warbler nestlings to make way for her own egg!

Brown-headed cowbirds are one of the few species in world that never take care of their own young. Instead they lay their eggs in other birds nests and rely on the foster care of other species to raise their babies for them. Recent experiments confirm that brown-headed cowbirds "farm" their hosts — the act of removing other removing other bird's eggs from their nests so they can create opportunities for themselves to lay their eggs in that nest. This strategy not only makes room for cowbird eggs but also resets the biological clock of the host species to lay new eggs and raise the cowbird baby alongside its own!

And cowbirds may have an even more dastardly trick up their sleeves—for more check out www.pbs.org/nova/sciencenow/

Video Credit: Phillip Elliot, Eastern Connecticut State University