(1739) Erythropus amurensis.
THE EASTERN RED-LEGGED FALCON.
Falco vespertinus var. amurensis Badde, Reis. Ost. Siberia, ii, p. 110 (1868) (Blagowestschensk, Amoor, E. Siberia). Erythropus amurensis. Blanf. & Oates, iii, p. 424.
Vernacular names. Daotu-hagra (Cachari).
Description.— Adult male. Face, crown,mantle and lesser wing-coverts slaty-black changing to grey on the rest of the head, wings, tail and upper plumage, the wing-quills washed with silver-grey and the edges of the inner webs more brown ; chin, throat, fore-neck and breast to upper abdomen grey; posterior abdomen, thigh-coverts and under tail-coverts deep ferruginous-red but often paler on the middle of the abdomen and under tail-coverts ; under wing-coverts and axillaries pure white.
Colours of soft parts. Iris dark brown; bill fleshy-red, paler and more yellow at the base, blackish at the tip; orbital skin orange-yellow, deeper during the breeding-season; legs orange-yellow to orange-red, claws pale fleshy-horny.
Measurements. Wing 230 to 246 mm.; tail 124 to 131 mm.; tarsus 28 to 33 mm.; culmen 16 to 18 mm.
Female. Upper plumage slaty-grey, very often tinged with brown on the head and nape and paler and purer grey on the rump, upper tail-coverts and tail; head- and neck-feathers black-shafted; remaining upper plumage barred with black, most densely so on the mantle,* subterminal band on tail broader than the rest; inner webs of outer primaries boldly barred with white, the bars becoming greyer and less conspicuous on the inner primaries and almost disappearing, except at the base, on the secondaries; in newly moulted plumage the -wing-coverts and scapulars are finely edged with white ; feathers round the eye, a patch below and a cheek-band black; lower parts creamy or pale rufescent white, with bold black longitudinal spots on the breast changing to spots and bars on the lower breast and flanks and disappearing altogether on the pale rufous posterior abdomen, vent, thigh-coverts and under tail-coverts; under wing-coverts and axillaries white barred and marked with black.
Young birds are like the female but browner, with the feathers of the upper parts, excluding the head, broadly edged with rufous; the wing-quills are black with broad white edges and practically no grey wash on the outer webs; the underparts are more heavily barred and the streaks on the breast are broader, generally ending in broad spatulate drops. Plumage intermediate between this and the adult stage is common. In young birds the colours of the soft parts are paler and duller.
Distribution. Siberia East of Lake Baikal to Manchuria, North China and casual as a breeder in the Eastern Himalayas. In Winter South to South China, North-East India and South and East Africa.
Nidification. This Red-legged Falcon breeds freely in N.E. China and Manchuria, where Vaughan and Jones, La Touche and Smirnoff took many nests and eggs. The nests used are nearly always those deserted by Magpies in trees round about villages and cultivation and often several nests occupied by the Kestrels may be found close together. In North Cachar it is only a casual breeder but there also I found two nests close to a village, one in a deserted Crow's nest and one in a nest not identifiable. The eggs vary from three to five, very rarely six and are typically but richly coloured Kestrels' eggs, many being extremely handsome. Fifty eggs average 35.8 x 28.9 mm.: maxima 38.9 X 28.9 and 38.2X 32.0 mm.; minima 33.0 x 27.1 mm. In China the birds breed from late June to the end of July but in North Cachar my two nests were taken on the 25th April and 16th May.
Habits. The Red-legged Falco us are migratory birds, leaving their normal breeding-haunts in the end of September and October and returning to them in March and April. They migrate in enormous numbers, which must be seen to be appreciated. One of their routes South ran through the Jetinja Valley in North Cachar and here in the last fortnight of October they arrived in countless numbers, looking like vast flocks of Termites as they soared about at an immense height in the clear blue sky. At night they descended to the bamboo-jungle to roost, when they were caught in thousands by the Hill Tribes, who go out with torches, drums and various barbarous musical instruments, so bewildering the wretched birds that they fall to the ground and are caught. Large numbers are eaten in the villages and the rest taken down to the plains, where they fetch a ready sale as pigeons ! The flight is like that of the true Kestrels and they may often be seen to hover when hunting for food and, though normally graceful and slow, yet the birds are capable of considerable spee when required. The cry is similar to the usual querulous cry of the Kestrel and is frequently uttered on the wing. They are easy birds to tame and thrive in captivity, whilst their nature seems to be very peaceable and even timid. The Chinese are said to employ them for hunting small birds but every stomach examined by me has contained nothing but insect-remains.