(580) Turdus dissimilis.
The Black-breasted Thrush.
Tardus dissimilis Blyth, J. A- S. B., xvi, p. 144, No. 12 (1857) (Lower Bengal; Himalayas). Merula protomelaena. Blanf. & Oates. ii, p. 133.
Vernacular names. Daokat gashim-gajao (Cachari).
Description.— Adult male. Whole head, neck and upper breast black, except extreme point of chin which is white ; remainder of upper plumage, wings and tail dark slate-grey, not sharply defined from the head; lower breast and flanks, axillaries and wing-coverts bright orange ferruginous; abdomen, sometimes also the centre of lower breast, vent and under tail-coverts white.
Colours of soft parts. Iris deep brown; eyelids pale yellow; bill orange-yellow in breeding-season, paler yellow in winter; legs and feet yellow to orange-yellow.
Measurements. Total length about 230 mm.; wing 118 to 125 mm.; tail 72 to 78 mm.; tarsus about 30 mm.; culmen about 20 mm.
Female. Whole upper plumage dark olive-brown; sides of head and ear-coverts ashy fulvous-brown, the shafts of the latter paler; chin and throat, white heavily streaked with brown, the spots forming almost confluent lines at the sides; upper breast olivaceous streaked with black; lower breast, flanks, axillaries and under tail-coverts orange-rufous: abdomen, vent and under tail-coverts white.
Colours of soft parts. Iris brown; bill, legs and feet wax-yellow.
Measurements. Wing 116 to 124 mm.; tail 84 to 86 mm.; tarsus 33 to 34 mm.; culmen 21 to 22 mm.
Nestling. Above, dark brown, the feathers with dark blackish edges and pale fulvous shaft-stripes; below, chin, throat and breast as in the female but more heavily spotted; remaining under parts orange-fulvous spotted and barred with black.
The young male is like the female but more spotted below.
Rothschild (Nov. Zool., xxvin, p. 31, 1874) shows that dissimilis of Blyth must be used for the name of this bird. It cannot be rejected merely because Blyth thought that Turdus unicolor was the female and Tardus dissimilis the male of the same species.
Distribution. Assam South of the Brahmaputra, Manipur, Chin and Kachin Hills, Shan States and Yunnan.
Nidification. The Black-breasted Thrush is resident throughout its habitat between 4,000 and 6,000 feet, wandering up to 7,000 or 8,000 feet in the Naga Hills, Chin Hills and Kachin Hills and up to 10,000 feet in Yunnan, where it was obtained by Forest on the Lichiang Range. It is essentially a forest breeder and all the nests I have taken were built well inside damp, evergreen forests on small trees or high shrubs. In appearance they are like rather small, untidy Blackbirds' nests, made more of green moss than anything else, and are placed at no great height from the ground. The eggs vary extraordinarily in colour, and in my own small series I have eggs exactly like Missel-Thrushes' eggs, others like Blackbirds' and others again very richly marked with bold blotches of deep reddish brown on pale green or pale cream grounds. They number three or four and are mostly laid in May and June but I have taken them in early April and again late in July. Fifty eggs average 26.8 x 19.8 mm.: maxima 29.0 x 20.0 and 27.2 x 81.0 mm.; minima 21.1 X 20.0 and 26.0 x 18.3 mm.
Habits. This is one of the most shy and elusive of all the bigger Thrushes, shunning observation and keeping almost entirely to the interior of forests. It occasionally ventures into the pine-woods round about Shillong in the Khasia Hills but prefers deep gloomy evergreen forests, which are always damp and shady. It is common in the tern and rhododendron forest and one often hears its short, sharp alarm rattle, though one seldom gets even a glimpse of it as it flees. It has a sweet but not very powerful song. Its food consists of insects and berries and it is a great snail and slug eater, finding them in the mossy cracks between the boulders in the forests it frequents.