(1104) Passer montanus obscuratus.
The Tibetan Tree-Sparrow.
Passer montanus obscuratus Jacobi, Abh. Ber. Mus. Tier. Dresden, xvi, p. 32 (1923) (Szechuan).
Vernacular names. None recorded.
Description. Similar to the European Tree-Sparrow but much larger. The material in the British Museum is very poor and the coloration differences, if any, are hard to define. The rump is almost as red as in P. m. malaccensis.
Colours of soft parts. " Iris dark brown ; bill black, gape yellow ; legs fleshy " ( Walton).
Measurements. Wing 76 to 82 mm.; tail 61 to 63 mm.; tarsus 16 to 17 mm. ; culmen about 10 to 11 mm.
Distribution. Tibet and Sikkim to Szechuan. A specimen obtained in the Abor Hills, wing 79 mm., seems to be of this race.
Nidification. The Tibetan Tree-Sparrow breeds from about 10,000 feet certainly up to 15,000 feet and possibly higher. It seems to keep even more exclusively to houses for breeding purposes than any of the other Tree-Sparrows, placing its nest - of the usual character - in holes in the roofs and walls and on the rafters. Barely it selects holes in trees and now and then it nests in stone boundary walls. The eggs are of the typical Sparrow type and one hundred average 20.8 x 15.1 mm.: maxima 22.0 x 15.3 and 21.0 x 15.9 mm.; minima 19.5 x 13.9 mm.
The breeding-season lasts from April to July, most eggs being laid in May and June.
Habits. This Tree-Sparrow is extremely common all over South and East Tibet to Szechuan between 12,000 and 15,000 feet; it occurs some two thousand feet lower, but not commonly, and certainly ascends to 17,000 feet, even if it does not breed at this elevation. To what extent it ascends and descends in Summer and Winter is not known but it is undoubtedly resident at 12,000 feet in the Gyantse plateau all the year round. It has the usual cheerful, chirpy habits of its species with nothing special calling for remark.