Species ( Caprimulgus vociferus ) of nocturnal North American bird, similar to the nightjar , named for its resonant "whip-poor-will" call (first and third syllables accented), which it may repeat 400 times without stopping.
It lives in woods near open country, where it catches insects on the wing around dusk and dawn. By day it sleeps on the forest floor or perches lengthwise on a branch. About 10 in. (25 cm) long, it has mottled brownish plumage; the male has a white collar and white tail corners. It winters as far south as Costa Rica.