The scissor-tailed nightjar (Hydropsalis torquata) is a species of nightjar in the family Caprimulgidae. It is distributed over much of eastern South America. Taxonomy The scissor-tailed nightjar was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the other nightjars in the genus Caprimulgus and coined the binomial name Caprimulgus torquatus. The scissor-tailed nightjar is now placed with three other species in the genus Hydropsalis that was introduced in 1832 by the German naturalist Johann Georg Wagler. The genus name combines the Ancient Greek hudro- meaning "water-" with psalis meaning "pair of scissors". The specific epithet torquata is from Latin torquatus meaning "collared". Two subspecies are recognised: H. t. torquata (Gmelin, JF, 1789) – south Suriname, Brazil and east Peru H. t. furcifer (Vieillot, 1817) – south Peru to south Brazil and central Argentina The specific epithet brasiliana or brasilianus was formerly sometimes used. Description The most distinctive feature of the scissor-tailed nightjar is the male's elongated outer tail feathers, which are almost twice as long as its body. Not including those feathers, the two sexes are long; including them, the male is up to long. Males weight and females . Males of the nominate subspecies have brown upperparts with grayish white speckles; the middle of the back also has blackish streaks and tawny spots. It has a broad tawny collar on the hindneck. The tail feathers are brown and the long outer pair have broad white tips. The chin is buffy, the throat buff or whitish with brown spots or bars, the breast buff with narrow brown bars, and the belly and flanks buff with wide brown bars. The wings are generally brown with tawny or buff streaks and spots, and do not have the white band that many other nightjars' wings have. The female's wings are tawnier, the tail has no white, and the outer tail feathers are only slightly longer than the inner ones. H. t. furcifer is larger than the nominate, generally paler, and its nuchal collar is buffier. The song is "a prolonged sequence of tsips...sometimes for minutes on end". It is given at dusk and dawn from a perch and in flight. It also has "an extremely high tsig" flight call and "a low clucking sound". Distribution and habitat The nominate subspecies of scissor-tailed nightjar is found