When warblers warn of cowbirds, blackbirds get the message

This is the story of three bird species and how they interact. The brown-headed cowbird lays its eggs in other birds’ nests and lets them raise its young — often at the expense of the host’s nestlings. To combat this threat, yellow warblers have developed a special ‘seet’ call that means, ‘Look out! Cowbird!’ In a new study, researchers report that red-winged blackbirds respond to the seet call as if they know what it means.