204 FRIGATE-BIRD 
coracoids meet the sternum, and the consequence is a bony frame- 
work which would be perfectly rigid did not the flexibility of the 
rami of the furcula permit a limited amount of motion. That this 
mechanism is closely related to the faculty which the bird possesses 
of soaring for a considerable time in the air with scarcely a per- 
ceptible movement of the wings can hardly be doubted, but the 
particular way in which it works has yet to be explained. 
Two species of /regata are considered to exist, though they 
differ in little but size and geographical distribution. The larger, 
F, aquila, has a wide range all round the world within the tropics, 
and at times passes their limits. The smaller, F. minor, appears to 
be confined to the eastern seas, from Madagascar to the Moluccas, 
and southward to Australia, being particularly abundant in Torres 
Strait,—the other species, however, being found there as well. 
Having a spread of wing equal to a Swan’s and a comparatively 
small body, the buoyancy of this bird is very great. It is a beau- 
tiful sight to watch one or more of them floating overhead against 
the deep blue sky, the long forked tail alternately opening and 
shutting like a pair of scissors, and the head, which is of course 
kept to windward, inclined from side to side, while the wings are 
to all appearance fixedly extended, though the breeze may be con- 
stantly varying in strength and direction. Equally fine is the 
contrast afforded by these birds when engaged in fishing, or, as 
seems more often to happen, in robbing other birds, especially 
Boostks, as they are fishing. Then the speed of their flight is 
indeed seen to advantage, as well as the marvellous suddenness 
with which they can change their rapid course as their victim tries 
to escape from their attack. Before gales Frigate-Birds are said 
often to fly low, and their appearance near or over land, except at 
their breeding-time, is supposed to portend a hurricane.! Generally 
seen singly or in pairs, except when the prospect of prey induces 
them to congregate, they breed in large companies, and Mr. Salvin 
has graphically described (/bis, 1864, p. 375) one of their settle- 
ments off the coast of British Honduras, which he visited in May 
1862. Here they chose the highest mangrove-trees? on which to 
build their frail nests, and seemed to prefer the leeward side. The 
single egg laid in each nest has a white and chalky shell very like 
that of a Cormorant’s. The nestlings are clothed in pure white 
down, and so thickly as to resemble puff-balls. When fledged, the 
beak, head, neck, and belly are white, the legs and feet bluish-white, 
but the body is dark above. The adult females retain the white 
beneath, but the adult males lose it, and in both sexes at maturity 
1 Hence another of the names— ‘ Hurricane-Bird’ —by which this species is 
occasionally known. 
2 Capt. Taylor, however, found their nests as well on low bushes of the 
same tree in the Bay of Fonseca (bis, 1889, pp. 150-152). 
