any of about 120 species of soft-plumaged birds, the major groups of which are called nightjars, nighthawks, potoos, frogmouths, and owlet-frogmouths. The order also includes the aberrant oilbird of South America. Most are twilight- or night-flying birds. Many produce sounds that are startling, strange, or weirdly beautiful. The calls of caprimulgiforms are surrounded by an aura of mystery richly endowed to elicit interest and sometimes fear from humans. The name of the type genus Caprimulgus, goatsucker, derives from an ancient belief that the birds seen flitting about the goats at dusk were taking milk from the goats' udders, a misconception no doubt fortified by the birds' uncommonly large mouths. In actuality, caprimulgiforms prey on the insects disturbed or attracted by the goats. There is now a tendency to replace the name goatsucker with the more appropriate term nightjar, derived from the birds' voices.
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