(1736) Microhierax melanoleucus melanoleucus.
THE INDIAN WHITE-LEGGED FALCONET.
Ierax melanoleucus Blyth, J. A. S. B,, xii, p. 179 (1843) (Assam). Microhierax melanoleucus. Blanf. & Oates, iii, p. 433.
Vernacular names. Doaling kashiba (Cachari).
Description. A narrow line across the forehead, lores, cheeks, supercilium and whole lower plumage white; whole visible portion of upper plumage, flanks, ear-coverts and a broad continuing line black; outer tail-feathers with white bars on the inner webs and a few broken ones at the base of the outer webs; wing-quills barred with white on the inner webs and some spots of white on the bases of the primary-coverts.
Colours of soft parts. Iris bright brown; bill deep slaty-blue to almost black, quite black at the tip; legs and feet dark horny-brown to black.
Measurements. Wing 111 to 117 mm.: tail 71 to 73 mm.: tarsus 22 mm.; culmen 14 to 15 mm. There are no males in the British Museum series.
Distribution. The whole of Assam from Jaipur in Kamrup, where Chennell found both this form and the Red-legged Falconet, to Dibrugarh on the extreme East. South it ranges to Cachar, Sylhet, Manipur (where I have obtained it) to Hill Tippera and probably Chittagong, whence I have had it reported. A race resident in Fokien, China, has been separated as M. m. sinensis and differs merely in having some white feathers indicative of a collar on the hind-neck. Some Dibrugarh specimens show several white feathers on the neck and, on the other hand, some Chinese specimens have none, so that the net difference might be held to be negligible.
Nidification. This grand little Falconet breeds from early March to the middle of May, depositing its eggs in the deserted nest-holes of Barbets or Woodpeckers. Like the nesting-holes of the rest of the genus the bottom of the hole is always full of insect debris, mostly the elytra of Coleoptera and wings of butterflies, etc., and on these, or among them, the eggs lay. Often the hole is one at a great height from the ground and quite inaccessible without the expenditure of great trouble and time, at other times it is lower down, between twenty and thirty feet. The eggs probably number three or four as I have seen this number of young just flown but 1 have never taken more than one egg. The average measurements of six eggs is 27.9 x 22.4 mm.: maxima 29.0 X 23.0 mm.; minima 24.0 x 20.4 mm.
Habits. This Falconet is found both in well-wooded open country and in forest, though in the latter it keeps much to clearings, banks of open streams and similar places. It occurs in the plains adjacent to the hills and ascends the latter to a height of about 5,000 feet but is more common below 3,000 feet than above. Its food consists principally of insects which it captures on the wing, sailing round in circles much like the Swallow-shrikes or pouncing on them from a perch on some lofty tree. It is also capable of great speed, sometimes swooping on its prey just like the true Falcons and striking them with the hind-claw, killing in this manner birds far larger than itself, such as Scimitar Babblers, Thrushes, etc. Insects are captured by the grasp of a foot and conveyed at once to the mouth and eaten; small birds and mammals are carried to a perch and larger ones eaten on the ground. A bird kept by me in an aviary completely cowed a number of Kestrels kept with it and also succeeded in killing a Woodpecker at least four times its own weight. Its heavy eyebrow, fierce black eye and general demeanour are all those of the largest and haughtiest of Eagles and its upright carriage is also similar. Its cry is a shrill scream and it also utters a low chattering call, whilst it expresses rage with a prolonged hiss.