(572) Turdus castaneus castaneus.
The Grey-headed Thrush.
Merula castanea Gould, P.Z.S., 1835, p. 185 (Sikkim); Blanf. & Oates, ii, p. 128.
Vernacular names. Lal Kastura (Hind.).
Description.— Adult male. Head grey, paling to almost white on chin, throat and posterior neck; back dark chestnut, lower back, rump and upper tail-coverts brighter chestnut; wings and tail very dark brown, the secondaries edged a little paler; below from neck chestnut, the centre oil the abdomen whitish and sometimes marked with black; under tail-coverts black with central streaks and broad edges of fulvous-white or white.
Colours of soft parts. Iris brown ; bill, legs and feet and eyelids wax-yellow to dusky yellow.
Measurements.— Male and female. Wing 130 to 142 mm.; tail 95 to 98 mm.; tarsus 33 mm.; culmen 2L mm.
Female. Much duller everywhere; the head and neck darker and brownish, the chestnut everywhere paler and margined below with obsolete pale greyish edges ; wings and tail lighter brown.
Colours of soft parts as in the male.
Nestling. Upper parts dark brown streaked with fulvous and becoming chestnut-brown on rump and upper tail-coverts, which have bright edges; below dull chestnut on sides of neck and breast, and on flanks changing to white tinged with rufous on the centre of these parts, all heavily barred with dark brown.
Distribution. From Kashmir to Sikkim and Bhutan. It is found in Assam m winter to the extreme East and South but some of these records may possibly refer to the next race.
Nidification. Breeds almost throughout Kashmir, Garhwal and West Nepal. How far it breeds to the East is very doubtful. Stevens does not think it breeds in Sikkim or, if it does, it does so at very high levels only and even in winter it is a rare bird. The nest is very like that of the Grey-winged Blackbird and is placed in similar positions. It, however, seldom, if ever, breeds below 6,000 feet and nearly always over 7,000 feet. The eggs are three or four in number, rarely five, long ovals in shape and are very like English Blackbird eggs, but generally more boldly marked and redder in tint. Fifty eggs average 30.6 x 21.6 mm.: maxima 35.0 x 21.0 and 29.6 x 22.8 mm; minima 28.1 x 21.2 and 32.5 x 20.6 mm.
The principal breeding months are May and June, but Marshall found eggs at Murree " just ready to hatch " on the 20 th of April.
Habits. The Grey-headed Thrush is found in summer from 7,000 feet up to 12,000 feet, descending to the foot-hills in winter and a short way into the plains. During the breeding-season it keeps much to evergreen forest, often some distance inside, but in the winter months it comes far more into the open and at thin time several birds may be seen together.