ORDER LONGIPENNES. 



LONG-WINGED SWIMMERS. J^GERS, GULLS, TERNS, ETC. 



Family STERCORARIID^. The Skuas 

 and Jaegers. 



Special Characters: Nostrils, separate and not tubular; bill, 

 with cere; front toes, palmate (full webbed); hind toe, small, but 

 always present and without web ; end of upper mandible (unguis ) , 

 swollen and somewhat rounded; plumage, always dark, sometimes 

 sooty, sometimes barred with brown; tail, never white or gray; 

 middle tail feathers, longest. The cere, a hard skin-like covering on 

 base of upper mandible, well distinguishes them from the Gulls. 



*GROUP 1. Wing, n to 15 inches long. 

 Under parts, not entirely pure white; bill, over 1.35; tarsus, over 

 i. 80; middle tail feathers, not pointed; plumage, sometimes dark 

 brown; sometimes mixed gray, brown, and white. 



Stercorarius pomarinus. 

 Pomarine Jaeger. 

 See No. 10. 



Bill, under 1.35; tarsus, under 1.80; middle tail feathers, pointed; 

 base of unguis to frontal feathers, less than length of unguis ; shafts of 

 primaries, yellowish white. Stercorarius longicaudus . 



Long-tailed Jaeger. 



See No. n. 



Bill, under 1.35; tarsus, under 1.80; middle tail feathers, pointed; 

 base of unguis to frontal feathers, greater than length of unguis; 



shafts of primaries, yellowish white. Stercorarius parasiticus. 



Parasitic Jaeger. 

 See page 288. 



* For directions for measurement see page 2 1 . 

 41 



