(1799) Buteo burmanicus.
THE JAPANESE DESERT-BUZZARD.
Buteo burmanicus Oates, Str. Feath., iii, p. 30 (1875) (Upper Burma). Buteo desertorum. Blanf. & Oates, iii, p. 393 (part.).
Vernacular names. As in B. vulpinus,
Description. Above dark brown, the feathers edged with rufous or buff; sides of head and neck rufous or buff with black streaks and a broad black or dark brown moustachial streak; lores white with black bristles ; tail dark brown, tipped paler and mottled rufescent and brown along the centre, the pale mottlings increasing on the outer tail-feathers; primaries blackish, edged grey and with the inner webs below the notch white, barred with dark brown; the white on the inner primaries changing to rufous; chin rufescent, streaked with blackish; throat, fore-neck and breast rufous or rufous-brown, the feathers sometimes edged with fulvous and nearly always black-shafted; lower breast and abdomen white barred with brown, in some specimens the brown occupying almost the whole of the abdomen; vent and under tail-coverts usually much less spotted with brown; thigh-coverts dark brown with a little white barring.
A dark phase, common in the Himalayas, is dark purple or chocolate-brown throughout; the head often with a little rufous edging to the feathers; ear-coverts rufous, lores and sides of forehead white; the tail-feathers are faintly barred and the quills are faintly barred and marked with white as in the normal specimens.
Colours of soft parts. Iris brown; bill slaty-brown to plumbeous-black ; the base rather paler; cere yellow; legs and feet yellow, claws black. The feathering on the tarsus varies ; in most birds it covers half, or rather more than half, the front but in some Himalayan specimens (= plumipes) it covers the entire tarsus to the base of the toes.
Measurements. wing 374 to 379 mm.; tail 198 to 209 mm.; tarsus 63 to 65 mm.; culmen 29 mm. wing 389 to 454 mm.; tail 225 to 248 mm.; tarsus 69 to 74 mm.; culmen 29 to 36 mm.
Young birds are paler brown above and the feathers have broader and paler buff or whitish edges and, in addition, are much barred and marked with white on the bases and inner webs ; the lores, forehead and a supercilium are white or pale buff; lower plumage white, pale buff or rufous, the breast, flanks and sometimes the abdomen streaked with dark brown; the thigh-coverts are dark brown or rufous-brown, barred with whitish, buff or pale rufous ; under tail-coverts pure white; tail paler and more rufous than in the adult and more mottled and barred with brown, the bars numbering as many as a dozen, the terminal six well-marked, the basal six broken and indistinct.
Distribution. Japan, Corea, China, Manchuria, Dauria, Turkestan and, possibly, the Northern Himalayas to Tibet and Ladak; in Winter South to India, Burma, Ceylon and rare in the Malay Peninsula.
Nidification. Two clutches of eggs, which I attribute to this Buzzard, were taken by Ruchbiel at Issikul on the 29th April and 28th May respectively. They measure on an average 57.1 x 46.2 mm.
Habits. The Eastern birds migrate in great flocks along the Chinese coast to South China and are then caught by the Chinese bird-catchers in large numbers; the more Western birds seem to migrate directly South to India, Burma and the Indo-Chinese countries. Its habits are much the same as those of other Buzzards but it is less restricted to open country and is sometimes found in the outskirts of forest and in well-wooded districts.