Nepal House Martin

The Nepal house martin is a non-migratory member of the swallow family, 13 cm long, mainly blue-black above with a contrasting white rump and white below. Unlike its close relatives, the Asian and common house martins, it has a black throat and black undertail, though the extent of the black chin varies clinally (Wikipedia, general species account).

It occurs in river valleys and rugged wooded mountain ridges at 1,000–4,000 m, nesting in colonies beneath overhangs on vertical cliffs, in enclosed mud nests with three or four white eggs. It is largely resident but descends to typically 300 m, occasionally 150 m, when not breeding, and has occasionally been recorded in northern Thailand in winter. Its range overlaps the Asian house martin's, though they breed at different altitudes (Wikipedia, general species account).