1071. Cypselus pacificus.
The Large White-rumped Swift.
Hirundo pacifica, Latham, Ind. Orn. Suppl. p. lviii (1801). Cypselus vittatus, Jard. & Selby, Ill. Orn. iv. pl. 39 (1840); Blyth, Cat. p. 86; Horsf. & M. Cat. i, p. 385; Blyth, Ibis, 1863, p. 369. Cypselus pacificus, Blyth, J. A. S. B. xiv, pp. 212, 548 ; Jerdon, Ibis, 1871, p. 355; Hume & Oates, S. F. iii, p. 43; Blyth & Wald. Birds Burm. p. 84; Hume & Dav. S. F. vi, p. 48; Hume, Cat. no. 101 bis; id. S. F. xi, p. 31; Hume & Inglis, S. F. ix, p. 246; Oates, B. B. ii, p. 1; Salvadori, Ann. Mus. Civ. Gen. (2) v, p. 573. Micropus pacificus, Hartert, Cat. B. M. xvi, p. 448.
Coloration. Upper plumage blackish brown; the feathers in young birds with pale edges, that grow indistinct in older specimens ; a broad white band, the feathers black-shafted, across the rump; chin and throat whitish, the shafts dark; rest of lower parts brown, each feather with a subterminal blackish band and a whitish edge at all ages.
Bill black; iris deep brown; feet purplish black (Davison).
Length 7; tail 3.2 ; wing 7; tarsus 0.45 ; the outer exceed the middle tail-feathers by about 1.25 inch.
Distribution. Assam, Cachar, and Manipur, throughout the Burmese countries and the regions to the eastward, from Japan to Australia.
Habits, &c. But little known ; it is even uncertain whether this species is resident in Burma. It was seen by Oates, generally in large flocks, flying at a considerable height, during the greater part of the year, but he doubts if it breeds in the country. It is known to breed on rocks and houses in islands off the coast of China.