16 Birds of Colorado 



Western Gull. Larus occidentalis. 



A.O.U. Checklist no 49 — Colorado Record — Cooke 97, p. 50. 



Description. — Adult — Mantle dark slatj' ; primaries, including the 

 inner webs of the first, second and usually the third, black tipped with 

 white ; rest of the pliunage white ; eyeUd vermilion ; bill clirome -yellow 

 with a vermiMon spot at the angle ; feet flesh-coloured. Length 24 ; 

 wing 16-5 ; culmen 2-30 ; tarsus 2-75. 



In winter adults have the top of the head and back of the neck 

 streaked with dusky. Young birds are brownish-slaty above, varied 

 with buS and whitish ; quills and tail-feathers dull black, usually 

 tipped with white ; under-parts brownish -grey, speckled with whitish ; 

 biU black. 



Distribution. — The Pacific coast, breeding from British Coltunbia 

 to Lower California, occasionally wandering inland. Its inclusion 

 in the Colorada a\Tfauna rests on the statement of Professor Wm. 

 Osburn, who informed Cooke he took an example at Loveland, 

 September 30th, 1889. 



Herring-Gull. Larus argentatus. 



A.O.U. Checklist no 51— Colorado Records— H. G. Smith 86, 

 p. 285 ; Morrison 89, p. 147 ; Cooke 97, p. 50 ; Felger 09, p. 277. 



Description. — Closely resembHng the Western Gull, but with a less 

 robust bill and hghter, paler blue mantle ; the outer primary is black, 

 becoming slaty towards the base, and has a white tip and subapical 

 white spot on both inner and outer webs, as a rule ; the other quills 

 are usually without the subapical spot, but have the white tip : iris 

 silvery to pale yellow, bill bright yellow with a vermilion spot on the 

 mandible, legs flesh-colour. Length 24; wing 17'18 ; culmen 2-40; 

 tarsus 2-75. 



In winter the head and neck are streaked with dusky and the bill 

 is duller. Young birds are mottled with dusky above and below ; 

 the wing and tail-feathers are dusky blackish, narrowly edged at the 

 tips with white ; iris brown, bill dusky blackish, flesh-coloured towards 

 the base. 



Disribution. — The Northern Hemisphere generally ; in America 

 breeding from Minnesota, the Great Lakes and Maine, north to 

 Labrador, Hudson Bay and perhaps Alaska ; in winter south to Cuba 

 and on the Pacific coast to Lower California. 



The Herring-Gull is only a straggler in Colorado ; a young bird shot 

 on a lake near Denver, November 17th, 1883, is said by H. G. Smith 

 to be preserved in the collection of A. W. Anthony ; Breninger informed 

 Cooke that he had observed it near Fort Collins. There is a young 



