DIRECTORY TO BIRDS OF EASTERN NORTH AMERICA. 37 



F. LO1VO- WINGED SWIMMERS, 



Lonjyi pennes . 



Water birds of varying sizes, with long wings and with 

 anterior toes webbed to a greater __?!? 38> 



or less extent, fig. 38 ; bill, vari- 

 able, but the nostrils are always 

 open, figs. 39, 50, plate 3; gula sac, 



absent ; color, variable, but often F 9 B, d. 3. 1-2 

 bluish or slaty above and white beneath ; some few species 

 are black above, and some brown or even dusky throughout. 

 Young, covered with down when hatched, plate 4, active, 

 but are fed by their parents. Food, mainly fishes, a few are 

 scavengers, and a few subsist partly upon insects. Inhabit 

 all regions of the globe on sea coasts or in the neighborhood 

 of large bodies of fresh water. Sexes, similar. 



A. SKUAS AND JAEGKERS. Stercorariidae. 

 Gull-like birds of large or medium size, dark above and 

 Fig. 39. also sometimes below; often 



banded below ; bill, strong- 

 ly curved with covering of up- 

 ss. per mandible composed of four 

 pieces, one at tip, one on eith- 

 er side and one at base, fig. 39 ; 

 A, b, 2. wings, long; tail, short, square 



with central feathers projecting beyond the others, figs. 41 ? 

 43, 44 ; toes, fully webbed. Ocean birds which breed on or 

 near the coasts of the colder waters of the world ; nests, placed 

 on the ground; eggs, 2 or 3, oval, brown or greenish-brown, 

 spotted and blotched with darker. Food, usually fishes oft- 

 en procured by robbing Gulls and Terns. Social when breed- 

 ing, solitary at other times. 



a. Skuas. Megalestris. 



Size, large, about that of Herring Gull; form, robust; 

 dusky brown throughout, a little lighter below ; central tail 

 feathers, only slightly projecting, fig. 40. 



