Grey nightjar
The grey nightjar is a species of nightjar found in East Asia, breeding from southeastern Russia south through China, the Korean Peninsula and Japan to northern Indochina and westward along the Himalayas. It is largely migratory, wintering in Indochina south to Java in Indonesia, but is resident in warmer areas in the south of its breeding range. It is sometimes treated as a subspecies of the jungle nightjar, its South Asian relative. The grey nightjar breeds and forages in early successional habitats surrounded by forests; its populations have declined since the 1970s in Japan. Like all nightjars, it is crepuscular to nocturnal, feeding on flying insects, including moths, beetles, flying ants, grasshoppers, and others.
Taxonomy
The species was formally described in 1845 by Coenraad Jacob Temminck and Hermann Schlegel with the binomial name Caprimulgus jotaka based on specimens collected in Japan. The specific epithet is the Japanese word for the species, Yo taka meaning "night hawk". The grey nightjar was subsequently included as a subspecies of the jungle nightjar until Rasmussen and Anderton split them in 2005 by the distinguishable calls and egg coloration. Both grey and jungle nightjar can be differentiated from other relatives that occur in same habitats by their different patterns on the tail feathers.Description
The grey nightjar is a medium-sized nightjar with a large head, large eye, long tail, weak bill and short legs. The plumage is mottled, very similar to the Himalayas subspecies of jungle nightjar. The forehead, crown, and nape are covered with small, intricate grayish-white and dark brown vermiculated patterns mixed with black longitudinal streaks, with the central black stripe on the crown being particularly prominent. The feathers on the nape have pale brown spots at the tips. The upper back to the upper tail coverts are of the same color as the crown, but with more dark brown horizontal bars. The scapulars are black with brownish-yellow spots, and the outer webs often have brownish-yellow patches. The wing coverts and remiges are dark brown, with the tips of the wing coverts displaying round brownish-yellow spots. The inner flight feathers are grayish-white with black shaft streaks and vermiculated patterns. The primaries and secondaries are edged with reddish-brown serrated markings. The first primary feather has a white circular patch near the center of the inner web, and the second to fourth primaries have white horizontal bars. The central tail feathers are gray-brown with dense dark brown vermiculated markings and 6 or 7 black wavy horizontal bands. The outer tail feathers are mostly dark brown with prominent white subterminal patches. The lores, supercilium, cheeks, chin, and throat are dark brown with yellowish-brown spots on the feather tips. The ear-coverts are yellowish-brown with black streaks. The throat has a conspicuous white patch. The chest is dark brown with pale brown horizontal bars, while the rest of the underparts are pale brownish-yellow, densely covered with dark brown horizontal stripes. Female has similar plumage to the male but slightly paler; the white throat patch is smaller and often tinged with brown; no white spots in the middle of the flight feathers, and no white subterminal patch on the tail feathers.File:Caprimulgus jotaka, National Museum of Nature and Science, Tokyo - DSC07280.jpg|thumb|Grey nightjar specimen in the National Museum of Nature and Science, Tokyo
Iris: Dark brown; Beak: Black; Tarsus and toes: Horny brown; Claws: Black.
Voice
The vocalization of nightjars is an important aspect to distinguish them in field. The grey nightjar song is a series of hollow byuck notes lasting 2–4 seconds and repeated at short intervals, like the firing of a cartoon laser gun. This song is a determinative evidence when splitting the grey nightjar from the jungle nightjar, that the jungle nightjar sings a long series of bouncing pooKIHpooKIHpooKIH notes.Distribution and habitat
The grey nightjar occurs throughout the South Asia to southeastern Russia, and east to Japan. The estimated extent of occurrence is 17700000 km². The resident range includes: Bangladesh, Bhutan, China, Hong Kong, India, Malaysia, Myanmar, Nepal, Pakistan, and Singapore; Some sedentary populations breed within the resident range while other migratory populations breed also in Japan, North Korea, South Korea, Mongolia and Vietnam. There are also some non-breeding occurrence in Brunei, Cambodia, Indonesia, Laos, Philippines, Russian Federation, and Thailand. Vagrants have been spotted in south Alaska, US.The grey nightjar habitat can be high, up to 3300 m in altitude, includes forest, shrubland, cliffs or mountain rocks, and anthropogenic constructions. This species primarily inhabits broadleaf forests and mixed broadleaf-coniferous forests, and can sometimes be observed in coniferous forests below an altitude of 1,400 m.Populations distributed in south China at altitudes ranging from 700 to 2,500 m.