420 PETRELS. 



flocks. Great quantities of them are destroyed by the crews of vessels, as well 

 as by the Esquimaux, their flesh being considered both wholesome and delicate, 

 and at the same time affording a beneficial change of diet to the mariner. 

 They are said to be very tame and easily captured, a circumstance readily 

 accounted for, as the persons engaged in the whale fisheries, and the limited 

 race of natives inhabiting the borders of the Arctic seas, arc the only human 

 beings by whom they are ever disturbed. Like the rest of its family, the little 

 auk passes a great portion of time on the ocean, where it sports with great 

 ease and fearless self-possession, feeding upon small Crustacea and fishes, 

 diving for its prey with great celerity and adroitness."" — GoULD, '■'^ Birds oj 



The Black Guillemot {Uria gryllc) is the type of another group, inhabi- 

 tants of the Arctic seas, whence they migrate during the winter to more tem- 

 perate regions. They are usually met with near the sea-coast, swimming and 

 diving with the greatest facility— assisting their progress under water with 

 their wings, and sometimes venturing even beneath the ice. Their flight is 

 short, rapid, and generally near the surface of the water, and they walk, Avhen 

 on dry land, with great difficulty. Their food consists of fish and other marine 

 productions. The females lay but a single egg, which is usually of large size, 

 on the ledges of precipitous rocks overhanging the sea, without even the 

 semblance of a nest. 



The colour of the plumage of these birds depends somewhat upon the lati- 

 tude. In winter, those that remain upon the northern shores of Britain are 

 mottled with black and white, but in higher latitudes they become entirely 

 white. It does not appear that this is caused by moulting the feathers : as soon 

 as the cold weather sets in the white begins to appear, and it gradually extends 

 over the whole plumage. 



FAMILY IV. 

 THE PETRELS. PROCELLARID/E. 



General Charactkristics. — Bill more or less lengthened, straight, more or less 

 compressed and grooved, as if composed of several pieces, with the tip strong, 

 arched, suddenly hooked and acute, and the nostrils tubular and exposed. 



The birds of the Auk family are very scantily furnished with 

 wings, and some of them are totally incapable of flight, but those 

 to which we have now to advert possess large wings, and fly with 

 great ease and rapidity.* Their body is tolerably short, supported 

 upon moderately long legs, which arc placed less backward than 

 in many of the preceding groups, so that these birds walk with 

 more grace than most of their allies. The anterior toes are well 

 developed, and united b}^ large webs, but the posterior toe is 



* Sec "Animal Creation," page 354. 



