(1776) Butastur indicus.
THE GREY-FACED BUZZARD-EAGLE.
Falco indicus Gmelin, Syst. Nat., i, p. 204 (1788) (Java). Butastur indicus. Blanf. & Oates, iii, p. 365.
Vernacular names. None recorded.
Description. Lores and a patch on either side of the forehead white ; sides and upper parts of the head and neck and the upper back greyish-brown with fine black shaft-lines; on the nape there is usually a patch where the white bases of the feathers show through; remaining upper parts brown, more or less tinged with rufous and black-shafted; upper tail-coverts tipped and barred with white; tail brown with two black bars and a third basal bar brownish-black the under aspect of the tail very pale; edge of wing white; greater coverts pale rufous-brown, with a subterminal indefinite brown band and edged with whitish; quills blackish-brown, paler on the inner webs which are barred with black and with white edges to the bases; in fresh plumage all the tips are edged pale; chin and throat white with a central and two side streaks of blackish, often very ill-defined; breast pale ashy rufous-brown with a few spots and bars of white; abdomen, vent and thigh-coverts white with rufous grey-brown bars, under tail-coverts white; under wing-coverts white with a few rufous bars; axillaries like the flanks and abdomen.
Colours of soft parts. Iris bright yellow; bill horny-yellow, blackish at the tips, the base, gape and cere orange-yellow; legs dull yellow, claws black.
Measurements. wing 315 to 325 mm.; tail 190 to 193 mm.; tarsus 55 to 59 mm.; culmen 27 to 30 mm. wing 322 to 336 mm.
Younger birds are like the adults but darker and browner and have four or five dark bands on the tail.
Young birds have the upper parts brown with dark shaft-stripes and pale edges to all the feathers; those of the crown edged with pale rufous and with white bases; the wing-coverts are all tipped with white and more or less barred with rufous-white; below white to buffy or rufous-white, streaked on the breast with rufous-brown and barred with the same on the abdomen and posterior flanks.
Distribution. All Burma to Tenasserim, through the Malay Peninsula to the Philippines, Celebes and New Guinea; Japan, China and the Indo-Chinese countries.
Nidification. This Buzzard-Eagle breeds in Japan and, according to Pere David, in the Mountains near Pekin. How far West it breeds is not known. According to Ouston it breeds commonly in the Southern Islands, building a nest like that of Butastur teesa in solitary trees in rice-fields or other cultivation. The eggs only differ from those of that species of Butastur in being larger. Twelve eggs average 49.0 x 39.7 mm.: maxima 52.0 X 40.3 and 49.5 x 41.3 mm.; minima 45.5 x 38.5 mm.
Habits. Apparently much the same as those of other Buzzard-Eagles but this bird is migratory instead of sedentary and in the Winter is found over a very wide extent of country.