Gulls. 



39. Ivory Gull (Pagopbila alba). L. 17. Ads. Pure 

 while; bill yellow; feet black. Yng. Similar, but wings 

 and tail tipped with blackish; throat dusky. 



Range.— Breeds in Arctic regions; winters south to Great Lakes 

 and British Columbia; rarely to Massachusetts. 



40. Kittiwake (Rissa tridactyla). L. 16. Hind toe 

 nail a knob. Ads. Head, neck all around, underparts, 

 and tail white; 3 in. or less, of tips of primaries black. 

 Yng. Tip of tail, ear-coverts, nape, and wing-coverts 

 with black; bill black; inner web of primaries with 

 white. Notes. A rapidly uttered kit-a-wake, kit-a- 

 wake. 



Range. — North Atlantic and eastern Arctic regions; breeds in Amer- 

 ica, from Gulf of St. Lawrence to Greenland; winters south to Great 

 Lakes, Long Island and, rarely, Virginia. 



40a. Pacific Kittiwake {Rtssa tridactyla pollicaris). 

 Similar to No. 40, but hind toe more developed; black 

 tips to 3 outer primaries, 3 in. or nore in length. Notes. 

 "A shrill, harsh cry when disturbed and a low whistle 

 when communicating with each other." (Nelson.) 



Range. — "North Pacific and Bering Sea; south in winter, casually 

 to southern California." (A. O. U.) 



41. Red-legged Kittiwake (Rissa orevirostris). Ads. 



Similar to Ad. of No. 40, but legs red, back and inner 



web of primaries darker; bill shorter, 1.2. Yng. Sim- 

 ilar to No. 40, but no black on tail or wings. 



Range. — Coasts and Islands of Bering Sea." (A. O. U.) 



54. Ring-billed Gull (Larus delawarensis). L. 18. 

 Ads. , summer, bill greenish yellow, a black band across 

 tip; ends of primaries black, a white spot near tip of 

 outer one. Ads. Winter. Similar, but head and neck 

 streaked with grayish. Yng. Tail grayish with a 

 broad black band; primaries black; back brownish gray 

 and whitish; belly white; end half of bill black. 



Range. — North America, coast and Interior; breeds from Newfound- 

 land, southern Minnesota, and British Columbia northward; winters 

 from Nova Scotia and British Columbia south to Cuba and Lower 

 California. 



55. Short-billed Gull {Larusbrachyrhynchus). L. 17; 

 B. 1.50 Ads., summer. Head, neck, tail, and underparts 

 white. Two outer primaries tipped with black, their 

 white spaces followed by black; remaining primaries 

 tipped with white. Yng. Grayish brown; basal half 

 of tiil pearl. Notes. "A sharp querulous kwew-kwew" 

 (Nelson.) 



Range. — North Pacific; breeds in Alaska and interior of northern 

 British Columbia; winters on coast from British Columbia to southern 

 California. 



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