(2196) Puffinus pacificus hamiltoni.
The Wedge-tailed or Green-billed Shearwater.
Puffinus pacificus hamiltoni Mathews, Birds of Aus., ii, p. 82 (1912) (Seychelles). Puffinus chlororhynchus. Blanf. & Oates, iv, p. 356.
Vernacular names. None recorded.
Description. Upper plumage dark brown, the head, wing-quills and tail almost black; lower plumage paler and more grey-brown, the chin and throat almost pure grey.
Colours of soft parts. Iris dark brown; bill dull fleshy or dusky greenish; legs and feet fleshy-white.
Measurements. Wing 274 to 290 mm.; tail 149 to 161 mm,; tarsus about 45 to 48 mm.; culmen about 36 to 39 mm.
Nestling in down pale grey, the throat and breast almost white.
Distribution. Breeding in Seychelles Mauritius, Fonquet and Rodriguez; Western Indian Ocean generally when not breeding and has occurred several times in Ceylon between Panadure and Colombo. It was also seen by Legge off Trincomalie ; whilst one is recorded by dimming as having been shot near Omara on the Mekran coast in May 1899.
Nidification, This Petrel breeds on the shores of the islands named in the preceding paragraph, burrowing out a hole in the soil about one or two feet deep and some six inches in diameter. There is no nest, the single egg being placed in a rather larger chamber on the bare soil. The egg is the usual pure white in colour. The only eight I have been able to measure average 68.0 x 42.3 mm.: maxima 72.1 x 43.6 and 66.1 x 44.8 mm.; minima 65.0 x 39.1 mm.
Both sexes assist in incubation but during the day one bird is always absent at sea; probably the female generally sits by day and the male by night.
The breeding-season is from December to February.
Habits. These Petrels are said to be very nocturnal or, at least, crepuscular in their habits, flying about more by night than day. They are powerful fliers and swimmers and feed by swimming and diving, taking small fish, cephalapods etc as well as feeding much on surface animalculae, which they take as they fly from the surface of the water. The call is a piping note, often heard at night.