GULLS 277 



gull, with a yellow beak and flesh-coloured legs, which is also a bird of the north, 



but not an Asiatic one, since it does not occur east of the White Sea. In America 



this gull (L. argentatus) breeds so far down as New Jersey on the Atlantic side, and 



California on the western coast. In summer the American birds appear in Mexico 



and the West Indies, while their European brethren wander to the shores of the 



Caspian, the Black Sea, and the Mediterranean. 



Greater Black- Its large size, coupled with the white head, the blackish back, 



Backed Gull. an d the flesh-coloured legs, serve to distinguish the great black-backed 



species (L. marinus), one of the boldest and strongest of its kind. This gull 



subsists largely on the prey it can steal from its relatives, as well as on their eggs 



and young. The breeding-area of this species extends into that of the truly Arctic 



gulls, and includes northern Europe, Iceland, Greenland, and Baffin Bay, while the 



winter migration takes these gulls to Egypt, the Canaries, and Florida. 



Lesser Black- From its larger namesake the lesser black-backed gull (L. fuscus) 



Backed Gull, differs not only by its inferior bodily size, but by its bright yellow 



legs. This gull breeds from the northern coasts of Europe to the Mediterranean ; 



and its range extends in winter down to the Bight of Benin, the Red Sea, and 



the Persian Gulf. In northern Asia and America this species is, however, 



unknown. 



Greater White- This gull (L. hyperboreus) is a truly Arctic species, breeding all 



Wmg-edGuii. r0lln( ] the pole, and ranging so far south as the Strait of Gibraltar, 



Florida, and Japan in winter. The largest of all the gulls, this species visits the 



British Isles, and is as omnivorous and rapacious as its black-backed relative, 



from which it differs in being wholly white with a slight pearly tinge, as well as 



by its shorter legs and wings. The nest is a conical heap of sand and seaweed, 



hollowed slightly at the apex, and frequently as much as a couple of feet 



in height. 



The beautiful Iceland gull (L. leucopterus) is likewise a pearly 

 Iceland GulL . . . . . 



white species, but only about two-thirds the size of the last, with 



much longer legs and wings and a shorter beak. Its breeding-area is circumpolar, 



and includes Jan Mayen, Iceland, Greenland, and Baffin Bay. In winter this gull 



occasionally straggles so far south as the British Isles on one side of the Atlantic 



and Boston on the other. An excellent diver, it feeds chiefly on live fish, and in 



pursuit of these it follows seals and other predaceous marine animals as they 



chase the shoals of small fish. The Iceland gull thus finds its food with little 



trouble, and at the same time indicates to sealers the whereabouts of their booty. 



Of the two kinds of fork-tailed gulls, the larger (Xema 

 Sabine's Gull. . <• 



furcatum) is South American, ranging as far north as the Galapagos 



Islands. The smaller Sabine's gull (X. sabinei), on the other hand, is Arctic, with 

 a circumpolar breeding-area. In winter it migrates to the North Sea, and in 

 America, where it is much more abundant, to the Gulf of Mexico, and, not im- 

 probably, on the Pacific side across the equator so far south as Callao. In these 

 gulls the head, back, and wings are grey, the head relieved by a black collar and 

 the wings by black primary quills. The beak is black tipped with red in both 

 kinds, but the larger species is distinguished by a white band at the base of the 

 upper half. 



