(764) Artamus leucorhynchos humei.
Hume's White-Rumped Swallow-Shrike.
Artamus leucorhynchos humei Stresemann, Nov. Zool., xx, p. 291 (1913) (Andamans). Artamus leucogaster. Blanf. & Oates, p. 499.
Vernacular names. None recorded.
Description. Head and neck slaty-grey, changing to purplish grey-brown on back, scapulars and lesser wing-coverts; rump, upper tail-coverts and whole under surface from breast pure white; tail blackish brown with very narrow pale tips.
Colours of soft parts. Iris pale blue, dark blue, to deep brown; bill pale blue, tipped with black ; legs and feet dark slaty to practically black.
Measurements. Wing 127 to 134 mm.; tail 55 to 60 mm.; tarsus about 15 to 16 mm.; culmen 16 to 17 mm.
Young. Barred above with rufescent and with dark blackish bars; wing-coverts narrowly tipped with pale rufous.
Distribution. Andamans and the Great and Little Cocos Islands. This form differs from typical leucorhynchos, as pointed out by Hume, in, being a far purer slaty, less sooty colour on the head and back.
Nidification and Habits differ in no way from those of the preceding species. Twenty-six eggs average 23.1 X 17.0 mm.: maxima 23.6 X 16.8 and 23.2 x 17.2 mm.; minima 22.3 x 17.1 and 23.0 x 16.5 mm. Mr. B. B. Osmaston says that they breed in March, April and May, almost invariably placing their nests on the broken-off stump of some stout branch of a tree.