(605) Monticola erythrogastra.
The Chestnut-bellied Rock-Thrush.
Turdus erythrogaster Vigors, P. Z. S., 1831, p. 171 (Himalayas). Petrophila erythrogastra. Blanf. & Oates, ii, p. 143.
Vernacular names. Ningri-pho (Lepcha) ; Daohangar (Cachar).
Description.— Adult male. Whole upper plumage brilliant cobalt-blue, the mantle blackish; lores, sides of head and neck black; chin and throat black suffused with blue; lesser and median wing-coverts like the back; quills blackish, the greater coverts, innermost secondaries and edges of quills dark cobalt-blue ; tail dark cobalt-blue, the feathers narrowly edged with brilliant blue ; remainder of lower plumage, axillaries and under wing-coverts chestnut-maroon.
Colours of soft parts. Iris hazel to deep brown; bill black; legs and feet plumbeous black to black.
Measurements. Total length about 220 to 230 mm.; wing 120 to 130 mm.; tad 100 to 104 mm.; tarsus about 29 mm.; culmen 21 to 22 mm.
In Winter for a short time after the Autumn moult the feathers of the mantle, sides of neck and lower throat are edged with whitish or pale fulvous, the inner secondaries and some of the coverts with white.
Female. Whole upper plumage, wings and tail olive-brown, the mantle obsoletely marked with dark crescentic bars becoming better defined towards the upper tail-coverts, where they are bold and black; a ring round the eye fulvous; lores mixed fulvous and olive-brown; ear-coverts blackish ; a patch behind them, an ill-defined moustachial streak and centre of chin and throat buff; remainder of lower plumage buff, barred with black and with pale edges, often worn away.
Colours of soft parts. Iris brown; bill dark horny-brown ; legs and feet dark brown.
Measurements. Wing 119 to 124 mm.
The Nestling is fulvous above, each feather boldly edged with black; below fulvous-white, barred and edged with blackish.
Distribution. Himalayas from Chamba to Eastern Assam, Manipur, the mountains of Burma, Cochin China to Western China and there are specimens from Fokhien. Chinese female birds are very dark and lack the fulvous-golden tinge on the lower plumage.
Nidification. This Rock-Thrush breeds between 4,000 and 8,000 feet throughout its habitat but principally under 6,000 feet. It makes a nest, roughly cup-shaped, of moss, twigs, roots, grass and other odds and ends, lined with fine roots or grass, which it places in a hole in a rock or cliff, in between stones or, more rarely, in a hollow in a bank or under a boulder or dead tree on the ground. Hume found a nest placed at the roots of a tree in forest but this situation must be exceptional.
The eggs vary from three to six in number. In ground-colour they range from creamy-white to pale reddish fawn, speckled all over, though more numerously at the larger end, with pale to fairly dark reddish brown. Most eggs look almost unicoloured but in a few the markings show fairly well. In shape they are broad ovals with a fine close texture, often highly glossed. Seventy-five eggs average 26.8 x 19.9 mm.: maxima 29.5 x 20.0 and 27.4 x 21.1 mm.; minima 24.3 x 19.6 and 26.6 x 19.0 mm.
The breeding-season is May and June.
Habits. In summer this is a wild shy bird, haunting the roughest of forest country, broken by cliffs and deep ravines, but in winter it becomes excessively tame and takes to the vicinity of villages and other human habitations, often perching on house¬tops and hunting for food in gardens and orchards. It will eat almost anything from the tiniest insects to the largest snails, worms, small lizards, frogs, etc. They will also eat small fish and water insects. In its actions generally it reminds one much of some of the Redstarts and these Thrushes show many connecting-links between the Phaenicurinae and Turdinae. Like the former birds they often capture insect prey from a fixed post, and they constantly jerk their tails backwards and forwards over their back.