"Nestling.--Covered with down of a sooty-brown color, except along the center of the back, along the carpal bend of the wing, on the breast and flanks, where it is dusky white; all the feathers of the back are dark brown, with a broad tip of ochraceous-buff; crown and ear-coverts blackish; eyebrow and throat white. "Observation.--Ospreys seem to get whiter on the head with age; but the mottling on the breast is at present unintelligible to me. It appears to be strongly marked in all old birds; but the brown centers to the feathers, which give the bird its mottled appearance, are never exactly similar, there being a continued alteration in the pattern of the feather itself. At the same time two young birds, distinguished by the fulvous margins to the upper surface, have not a similar amount of brown on the breast; for in one it is almost entirely absent, while the other has very few markings indeed. The tail becomes more uniform brown with age, so that a strongly barred tail is a sure sign of immaturity." (Sharpe.) 204. PANDION LEUCOCEPHALUS Gould. AUSTRALIAN OSPREY. Pandion leucocephalus Gould, Syn. Birds Austr. (1838), pt. 3, pl. 6; Sharpe, Cat. Birds Brit. Mus. (1874), 1, 451; Hand-List (1899), 1, 279; North, Catal. Austral. Bds. ed. 2 (1898), pt. 1, 70; Oates, Cat. Birds' Eggs (1902), 2, 317; McGregor and Worcester, Hand-List (1906), 45. Balabac (Everett); Luzon (Worcester); Marinduque (Steere Exp.); Palawan (White). Australia and Austro-Malayan Islands. "Similar to P. haliætus, but very much smaller; cere bluish lead-color; bill black; feet pale bluish white; iris primrose-yellow in some, bright orange in others. Length, 508; wing, 414. A specimen killed by Mr. Wallace in New Guinea had the wing 432 long." (Sharpe.)