(1728) Falco severus severus.
THE BURMESE HOBBY.
Falco severus Horsf., Trans. Linn. Soc, xiii, p. 135 (1822) (Java) ; Blanf. & Oates, iii, p. 423 (part.).
Vernacular names. None recorded.
Description. Head, hind-neck and upper back almost black, just tinged with slaty, changing gradually into dark slaty-grey on the lower back, scapulars, wing-coverts, rump, upper tail-coverts and tail, each feather with a black shaft; central tail-feathers faintly barred darker, very old birds having only one subterminal blackish band ; lateral tail-feathers more boldly barred ; primaries black, the inner concealed webs with short bars or spots or pale ashy-rufous; outer secondaries with fainter spots and inner secondaries grey like the scapulars; sides of the neck, chin and throat white tinged with orange-rufous ; remainder of lower parts deep ferruginous-red, often showing traces of black streaks on the sides of the breast.
Colours of soft parts. Iris hazel-brown to almost black ; bill bluish-slate, the tip black and the base paler; cere, gape and orbital skin lemon-yellow; legs and feet yellow to almost orange-yellow, claws black.
Measurements. Wing 221 to 238 mm.; tail 95 to 110 mm.; tarsus about 30 to 33 mm.; culmen about 18 mm. (Apparently all females.)
Young birds are very dark above, the feathers when first moulted with narrow rufous edges, soon lost, by abrasion; the under surface is boldly streaked with black from upper breast to under tail-coverts.
Distribution. Assam, Cachar, Manipur, Arakan, Kachin Hills, Tenasserim, Siam (Malay States?) to the Philippines. East to Trang Bong in Cochin China.
Nidification. The Burmese Hobby breeds in some numbers in the Cachar and Khasia Hills, almost invariably selecting an old nest of a Crow or other bird built in a tree on the face of a very steep cliff. Rarely the nest is placed on a ledge of rock and when this is the case it is very roughly and carelessly built, probably by the birds themselves, whilst in one case in Burma P. Macdonald found a solitary young bird in a hole in the high earth-bank of the Mugitha River. In the Khasia Hills each pair of birds seemed to have two nests, which they used in alternate years or to which they resorted if the first set of eggs were taken. The eggs are like those of the other races but much more richly coloured than those of the European Hobby. Fifty-four eggs average 40.1 x 31.9 mm.; maxima 41.4 x 33.0 and 41.1 x 34.0 mm.; minima 37.1 x 30.9 and 38.4 x 30.0 mm. The breeding-season lasts from April to June and I think some birds rear two broods in the season.
Habits. Like all other Hobbies these are birds of well-wooded country, but they never appear to penetrate deep woods and prefer scattered copses or singletrees. They feed on insects, the larger Coleoptera, small birds and bats, some individuals confining themselves almost entirely to the last-named. These they catch by a steady pursuit and not by the wild dash and stoop by which small birds are captured. All those I saw taken were grabbed in the air and then carried off to a tree to be eaten. Every pair of Hobbies have their own hunting-ground, which they guard most jealously from others of their own species yet share in amity with Peregrines and other larger Raptores. I have seen remains of Barbets, Bulbuls, Bustard-Quail and other birds lizards, mice, rats, etc., in or under their nests. Their cry is a loud squealing note and when enraged they repeat this cry continuously until the intruder retires. Like all Hobbies they are very crepuscular in their habits and very seldom hunt during the hotter hours of the day, even when the young are hatched.