Gulls 387 



slate, or nearly black, and the head is often more or less marked with black in 

 summer. The seasonal change is not great, and affects chiefly the color of 

 the head, which, in species with black heads, turns white in winter, while 

 the White-headed Gulls usually get that par streaked with dark during the 

 same season." 



The range in size among the Gulls is considerable, the smallest being the Little 

 Gull (Larus minutus) of sub-Arctic and temperate Europe and Asia, which is only 

 eleven inches in length, and the largest is the Great Black-backed Gull (L. 

 marinus) of the North Atlantic, which is from twenty-nine to fully thirty-two 

 inches long. In habits the Gulls are all very similar, feeding largely on fish and 

 such scraps and refuse as finds its way into bays and harbors. Off every sea- 

 port town may be found at all times a noisy, quarrelsome horde of various Gulls. 

 They are gregarious at all seasons, but especially so during the nesting period, 

 when they congregate to the number of hundreds, thousands, and in some cases 

 almost millions, where their screaming "overnoises the thunder of the surf." 

 The nests are placed on the ground, on bare ledges of rock, or in some species 

 among the rank grasses on islands and shores, and the eggs number from two 

 to four, with a pale brownish, light bluish, or bufify ground color, irregularly 

 spotted or blotched with brown and lavender. 



The Gulls are divided into seven or eight genera, the typical and largest 

 being Larus, with forty-five species or forms. About thirty species of Gulls are 

 found either regularly or occasionally in North America, and about a dozen 

 in Great Britain. Among them all it will be possible to mention only a few of 

 the more conspicuous or interesting. 



Ivory Gull. On the basis of the tarsus being roughened or serrated behind, 

 the beautiful Ivory Gull (Pagophila eburned] is placed in a genus by itself. It is 

 of medium size, the length being from fifteen to nineteen inches, with the plumage 

 pure white throughout, although the young are sparingly spotted with black, 

 while the bill is greenish yellow and the feet jet-black. This species is circum- 

 polar in distribution, breeding mainly in Spitzbergen and coming south in win- 

 ter along the coasts of northern Europe and as far as Newfoundland and New 

 Brunswick on the American side. 



The Kittiwakes (Rissa), of which there are three forms, are separated mainly 

 on the ground of the hind toe being rudimentary or entirely absent. With the 

 exception of a bluish gray mantle the plumage is also pure white, the legs and 

 feet in the Common Kittiwake (R. tridactyla) of the North Atlantic, and its sub- 

 species, the Pacific Kittiwake (R. t. pollicaris] of the North Pacific, being black 

 or dusky and bright red in the Red-legged Kittiwake ( R. brevirostris) of the coasts 

 and islands in Bering Sea. In writing of the birds of the Pribilof Islands, 

 Mr. Palmer says the last is the "most beautiful species on the islands. Always 

 graceful, whether on the cliffs or flying, its beautiful form and delicate snow- 

 white plumage, with its vermilion feet, adds much to the avifaunal wonders of 

 these islands." It breeds abundantly on the Pribilofs, placing the nest, which 

 Mr. Elliott says is quite substantially made of dry grass and moss cemented with 

 mud, on the most inaccessible shelves and points of rock, where it can seldom 



