Nightjars are medium-sized nocturnal or crepuscular birds in the familyCaprimulgidae, 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.
The English word 'nightjar' originally referred to the European nightjar.
Nightjars are found around the world. They are mostly active in the late evening and early morning or at night, and feed predominantly on moths and other large flying insects.
Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is cryptically coloured to resemble bark or leaves. Some species, unusual for birds, perch along a branch, rather than across it. This helps to conceal them during the day. Bracken is their preferred habitat.
The common poorwill, Phalaenoptilus nuttallii is unique as a bird that undergoes a form of hibernation, becoming torpid and with a much reduced body temperature for weeks or months, although other nightjars can enter a state of torpor for shorter periods.
Nightjars lay one or two patterned eggs directly onto bare ground. It has been suggested that nightjars will move their eggs and chicks from the nesting site in the event of danger by carrying them in their mouths. This suggestion has been repeated many times in ornithology books, but while this may accidentally happen, surveys of nightjar research have found very little evidence to support this idea.
The Collaborative International Dictionary
Goatsucker \Goat"suck`er\, n. (Zo["o]l.) One of several species of insectivorous birds, belonging to Caprimulgus and allied genera, esp. the European species ( Caprimulgus Europ[ae]us); -- so called from the mistaken notion that it sucks goats. The European species is also goat-milker, goat owl, goat chaffer, fern owl, night hawk, nightjar, night churr, churr-owl, gnat hawk, and dorhawk.
Douglas Harper's Etymology Dictionary
nocturnal bird, goatsucker, 1620s, from night + jar (v.). So called for the "jarring" sounds made by the male when the female is brooding, which have been described as a "churring trill that seems to change direction as it rises and falls." An Old English word for it was nihthræfn "night raven."
n. Any of various medium-sized nocturnal birds of the family Caprimulgidae, that feed predominantly on moths and other large flying insects.
Usage examples of "nightjar".
Hours later, crickets chirruped and nightjars cooed as evening stippled the jungle canopy with scattershot stars.
The only sounds were their out-of-breath gasps as they pistoned their fists into him and the liquid twitter of a nightjar in the deep stand of pine close by.
We are rich in nightjars, as you know - do you hear the one over to the east?
After a while, during which at least three separate nightjars churred and one owl called, she said, 'Stephen, you do me infinite honour, and it grieves me more than I can say to desire you to dismiss the subject from your mind.
There were few birds he preferred to nightjars, but it was not that they had brought him out of bed: he stood leaning on the balcony rail and presently Jack Aubrey, in a summer-house by the bowling-green, began again, playing very gently in the darkness, improvising wholly for himself, dreaming away on his violin with a mastery that Stephen had never heard equalled, though they had played together for years and years.
Every so often, their glow would briefly light up other, larger shapes: bats and nightjars swooping down to take advantage of the feast set out before them.