The swallow-tailed nightjar (Uropsalis segmentata) is a species of nightjar in the family Caprimulgidae. It is found in Bolivia, Colombia, Ecuador, and Peru. Taxonomy and systematics The swallow-tailed nightjar shares its genus with the lyre-tailed nightjar (Uropsalis lyra) and has two subspecies, the nominate U. s. segmentata and U. s. kalinowskii. The nominate was originally described as Hydropsalis segmentata and U. s. kalinowskii as a separate species, Macropsalis kalinowskii. Description The male swallow-tailed nightjar has extremely long outer tail feathers from which the species gets its name; the female's tail is much shorter and less graduated. The male is long including the tail streamers and weighs about . The female is long and weighs about . The upperparts of both sexes of the nominate subspecies are dark brown with many tawny spots. The tail is generally brown; the outer tail feathers of both sexes have white shafts and outer webs and the others have tawny bars and spots. The wings are brown to grayish brown with tawny spots. The chin and throat are dark brown with buff spots, the breast dark brown with tawny and buff scallops, and the belly and flanks buff with brown bars. U. s. kalinowskii has a somewhat shorter tail, the white on the outer feathers is barred rather than continuous, and the inner tail feathers have a whitish band near the tip. Distribution and habitat The swallow-tailed nightjar is a bird of the Andes. The nominate subspecies is found in Colombia and Ecuador and U. s. kalinowskii in Peru and Bolivia. In Colombia it is found in the Central and Eastern Andes, on the main Andes' west slope in northern Ecuador and northwestern Peru, and on the east slope for the entire length of Ecuador, most of Peru, and well into Bolivia. In Colombia it ranges from of elevation, in Peru from , and in Bolivia from . In Ecuador it is mostly found from but also as low as in Napo Province. The swallow-tailed nightjar typically inhabits elfin forest but also the edges of humid montane forest and openings with bamboo, grass, or shrubs. Behavior Feeding The swallow-tailed nightjar is crepuscular and nocturnal. It forages by sallying from the ground or a low perch and also during low continuous flight over open areas. It preys on insects, though details of its diet have not been studied. It roosts on the ground during the day.