42 BUTEONIN A. 
Haliacétus leucogaster, Gri. 
43.—Jerdon’s Birds of India, Vol. I, p. 84; Butler, Deccan and 
South Mahratta Country; Stray Feathers, Vol. IX, p. 373; 
Hume’s Scrap Book, p. 259. 
THE GREY-BACKED SEA EAGLE. 
Female.—Length, 30 ; expanse, 84; tail, 11°5 ; wing, 23; tarsus, 
4; bill from gape, 2°65. 
Male.—Length, 26°75 ; expanse, 74; tail, 9°83; wing, 21; tarsus, 
4; bill from gape, 2°4. 
Bill, upper mandible pale leaden-brown, bluish at junction with 
cere ; lower mandible pale blue, brownish at tip; irides brown ; 
cere and gape pale leaden color ; legs and feet white, tinged more 
or less greenish-brown. 
Adult : head, neck and entire under parts pure white; mantle 
and wing pale blue-grey; quills and tail cinereous black, the 
latter broadly tipped with white. 
The young bird has the mantle and wing-coverts brown, the 
white parts fulvous-white, tinged with rusty-brown, and dusky, 
especially on the head, breast and middle of the abdomen; and 
the tail is dark with spots and speckles. 
Wings reach beyond the end of the tail, which is much rounded 
or somewhat wedge-shaped. Its talons have trenchant inner 
edges, and the feet are rough beneath. 
The Grey-backed Sea Eagle is not uncommon on the Sea-coast. 
A large colony frequents and breeds upon Pigeon Island. 
They appear to subsist chiefly upon sea snakes, as the 
ground beneath their nests (which are generally built upon 
high trees) is strewed with their bones. It is also called the 
White-bellied Sea-Eagle. 
SuB-FAMILY, Buteonine. 
Bill small or moderate, rather weak ; wings long or moderate; 
tail short, or moderately long in a few; tarsi rather long, with 
scutz both in front and behind; feet short ; hind-toe short. 
Genus, Buteo, Cuvier. 
Bill short, sloping from the base, tip hooked, margin of the 
upper mandible very slightly festooned ; nostrils large, oval, trans- 
verse ; gape, wide ; lores clothed with hair-like feathers ; wings 
long, with the third and fourth quills sub-equal and longest, fifth 
quill nearly as long ; the inner web of the first four quills strongly 
notched ; tail moderate, or short, even or rounded; tarsi rather . 
long, feathered on the upper third or further; tarsal scales broad, 
transverse ; toes with four or five large scales at their extremity 
only ; lateral toes very unequal; all toes short. 
Buteo ferox, S. G. Gmelin. 
45,-—Buteo canescens, Hodgs—Jerdon’s Birds of India, Vol. I, 
