Nightjars are medium-sized
nocturnal or
crepuscular birds in the
family Caprimulgidae, characterized by long wings, short legs and very short bills. They are sometimes called
goatsuckers, due to the ancient folk tale that they sucked the milk from goats (the
Latin for goatsucker is
Caprimulgus). Some
New World species are called
nighthawks. Nightjars usually nest on the ground.