CARNIVOROUS BIRDS 53 



two of these. H. O. Forbes (in A Nahiralisfs Wanaerings in 

 the Eastern Archipelago) describes the piratical habits of the 

 smaller species, which pursues tactics much like those already 

 mentioned when dealing with the skuas. Speaking of the birds 

 of the Keeling Islands, he says: "Graceful Noddies {Anous 

 stolidus) and Gannets [Szila piscatrix) were in thousands, and 

 I had the satisfaction of watching . . . how their industrious 



Fig. 344. — Frigate-Bird [Fregatus) 



habits are taken advantage of by the swift-winged frigate-birds. 

 Hiding in the lee of the cocoa-nut trees, [they] would sally out 

 on the successful fishers returning in the evening, and perpetrate 

 a vigorous assault upon them till they disgorged for their behoof 

 at least a share of their supper, which they caught in mid-air as 

 it fell. . . . Refractory gannets were often seized by the tail by 

 the frigate-birds, and treated to a shake that rarely failed of suc- 

 cessful results." 



Albatrosses (see vol. i, p. 182) and Stormy Petrels are re- 

 spectively the largest and smallest of the web-footed birds. They 

 are representatives of two allied families belonging to the Tube- 

 nosed Birds (Tubinares). 



The two groups of Diving Birds (Auks, Guillemots, Puffins, 

 Divers, and Grebes) (fig. 345), and Penguins include those birds 

 which are most expert at pursuing fish in the water, and the 

 latter group represents the extreme term in the series of structural 

 modifications for this purpose (see vol. i, p. 187). But this perfect 

 adaptation to an aquatic life is only gained by the complete loss 

 of powers of flight, and great limitation as regards progression on 

 land, for the wings of Penguins are only useful as paddles, and 



