NORTH AHEBICAN BIRDS. 29 



in June. The nests are built of sea ferns and dry grass, placed among the grassy 

 tussccks in the center of the island. The eggs are two, sometimes three in number; 

 their general shape is spherically oval, and the ground color dark grayish-brown, 

 pale ash, pale clay or a pearly white. The markings are small patches of light 

 brown and brownish black. The sizes range from 2.95 to 3.15 long by 2.18 to 2.26 

 broad. 



42. 1. POIIIT BABBOW GTJLL. Larus iarrovianus Ridgw. Geog. Dist. — 

 Bering Sea and adjacent waters, northeastward to Point Barrow, southwest in winter 

 to Japan. ' 



This new species of Gull, whose plumage is described as resembling that of the 

 Glaucous and Iceland Gulls, and whose size is intermediate between these two 

 species, is found on the islands of Bering Sea, and its range extends as indicated in 

 the geographical distribution. It has proved to be distinct from the Atlantic coast 

 species. Specimens that served for description were from the Island of St. Michaels 

 and Point Barrow.* Nelson says: "The solitary islands of Bering Sea and all its 

 dreary coast line are familiar to this great gull." On June 4 their first nest was 

 found. It was placed on a small islet, a fev;' feet across, in the center of a broad, 

 shallow pond. The structure was formed of a mass of moss and grass piled up a foot 

 or more high, with a base three feet across, and with a deep central depression lined 

 with dry grass. There was a single egg. The female as she sat on the nest was 

 visible a mile away and not the slightest opportunity was afforded for concealment 

 on the broad surrounding flat. An equally 'conspicuous structure was found near St. 

 Michaels on June 15. The majority of the nests found were situated on a small islet 

 in a pond. The nest found on June 15 was a bulky structure made up of tufts of 

 moss and grass rooted up by the birds' beaks. The ground near the nest looked as 

 though it had been rooted up by pigs. Mr. Ridgway gives the measurement of the 

 eggs as 3.05x2.03. One of the eggs taken by Mr. Nelson was white, without a trace 

 of the usual color marks. 



43. ICELAIXD GULL. Larus leucopterus (Faber.) Geog. Dist. — Arctic 

 Regions, south in winter In North America to Massachusetts, and farther. 



This Gull is precisely like the last, but smaller, and it is dilficult to distinguish 

 the two at a distance. Another common name for it is White-winged Gull. It is 

 an Arctic species, and its distribution during the breeding season is nearly identical 

 with that of the Burgomaster, being found in the northern parts of Europe, Asia and 

 North America. Mr. Hagerup states that on Arsuk fjord in South Greenland about 

 a thousand pairs nest on what is known as "bird cliff," above the Kittiwake Gulls. 

 The lowest nests are built at a height of about two hundred feet; the highest about 

 five hundred feet above the sea level. The two species are often found nesting in the 

 same places, and the nests are of the same construction. The eggs, however, are 

 smaller, measuring 2.79x1.85. The Iceland Gull is, according to Mr. Nelson, the most 

 abundant species along the coasts and about the islands of Bering Sea, thence along 

 the adjoining Arctic coasts. It was found abundant on the Yukon, from Anvik to 

 the sea by Mr. Dall, who secured its eggs there from the 5th to 10th of June. The 

 eggs were laid in small depressions in the sandy beaches of the islands in the river. 



44. GLAXJCOTTS-WINGED GULL. Larus glanicescens Naum. Geog. Dist.— 

 Pacific coast of North America', from Alaska south to California on the Asiatic aide 

 south to Japan. 



t For details see Auk, III, p. 33», or RIdrway's Manual N. Ar.i. Birds, p. 26. 



