294 FRIGA TE-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 Fregata 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 apiDeai-ance fixedly extended, though the breeze may be con- 

 stantly varying in strength and direction. Equally fine is the 

 contrast afibrded by these birds when engaged in fishing, or, as 

 seems more often to happen, in robbing other birds, especially 

 Boobies, 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 coiu"se 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 (Ibis, 1864, p. 375) one of their settle- 

 ments off the coast of British Honduras, which he \dsited 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 



^ Hence another of the names — ' Hurricane-Bird ' — by which this species is 

 occasionally known. 



" Capt. Taylor, however, found their nests as well on low bushes of the 

 same tree in the Bay of Fonseca {Ibis, 1889, pp. 150-152). 



