GREAT BLACK-BACKED GULL. 

 saddle-back. cobb. 



Larus marinus. 



Char. Mantle slaty brown ; outer wing-feathers more or less black, 

 tipped with white ; rest of plumage white ; bill yellow, red at the angle, 

 legs and feet pink. Length about 30 inches. 



The full plumage is not assumed until the fourth year Immature 

 birds are mottled brown and white, very young specimens having the 

 upper parts almost entirely brown, and the bill dusky. 



Nest. On an inaccessible cliff by the sea, or upon a rocky island in a 

 lake, — a mere depression in the turf, lined with grass or sea-weed ; some- 

 times a bulky affair made of coarse herbage and lined with grass and a 

 few feathers. 



Egf:;s. 2-3 (usually 3) ; buffish gray to deep buff, sometimes slightly 

 tinged with olive, boldly blotched with brown and gray ; average size 

 about 300 X 2.10. 



The Saddle-back, or Black-backed Gull, is a general denizen 

 of the whole northern hemisphere, and extends its residence in 



