GULLS AND TERNS 21 



42. Larus glaucus Brlinn. GLAUCOUS GULL. 



Primaries white or light gray, shading 1 into white at ends. Adults in 

 summer: mantle, i. e. back and top of wings, light pearl gray; rest of 

 plumage white. Adults in winter : head and neck streaked with grayish. 

 Young : whitish, tinged, below and mottled above with brownish gray. 

 Length : 26-32, wing 16.75-18.75, bill 2.30-2.70. 



Distribution. Arctic regions ; in North America south in winter to 

 North Carolina, the Great Lakes, and San Francisco Bay. Not common in 

 the United States. 



Nest. A depression in a ledge of rock, lined scantily with fine grass, or 

 a bulky mass of sod and tufts of moss on an islet in a pond. Eggs : 2 or 3. 



The glaucous gull has been found by Mr. Loomis at Monterey, 

 and by Dr. Cooper and Mr. Kobbe in San Francisco Bay. 



44. Larus glaucescens Naum. GLAUCOUS-WINGED GULL. 



Adults in summer. Mantle light pearl gray ; primaries gray, with dis- 

 tinct white tips ; rest of plumage white. Adults in winter: head and neck 

 clouded with sooty gray. Young: deep ashy gray; head and neck 

 streaked, and rest of upper parts mottled with grayish white or dull buff. 

 Length: 23.70-27.75, wing 16.25-17.30, bill 2.20-2.60, depth of bill at 

 angle .80-.90. 



Distribution. From Bering Sea south in winter to southern California 

 and Japan. 



Nest. Usually on the face of a rugged cliff, but sometimes in grass on 

 grassy islands, or a depression in seaweed. Eggs : 3. 



Mr. Kobbe says that the glaucous-winged gulls are abundant in 

 San Francisco Bay in winter, and Mr. Loomis has found them com- 

 mon in Monterey Bay. Mr. Loomis says they make up the greater 

 number of gulls in the large trains of gulls and pelicans that attend 

 the whales that come into the bay. Near the ocean, in the Carmel 

 valley, lie has found them in company with western gulls following 

 the plough like blackbirds. 



At Gray's Harbor, Washington, Mr. Lawrence says the gulls are 

 very common from fall until late spring. During the salmon runs 

 they often fly thirty miles to feed on the dead salmon along the 

 streams, returning to the harbor to roost. The gulls also visit the 

 salmon canneries to feed on the refuse. 



49. Larus occidentalis Aud. WESTERN GULL. 



Adults in summer. Mantle dark slaty gray ; primaries, including inner 

 webs of first, second, and usually third black, tipped with white ; rest of 

 plumage white. Adults in winter : top of head and back of neck streaked 

 with dusky. Young : upper parts brownish slaty, varied with buff and 

 whitish ; quills and tail dull black, usually tipped with white ; under parts 

 brownish gray, specked or spotted with whitish. Length : 24-27, wing 

 15.75-17.00, bill 2.00-2.35, depth of bill at angle .S5-.95. ' 



Distribution. Pacific coast from British Columbia to Cape St. Lucas. 

 Lower California. 



Nest. A depression in seaweed. Eggs ; usually 3, light grayish olive, 

 spotted with shades of brown and lilac. 



