FAMILY STERCORARIID.E. SKUAS AND J.EGERS. 33 



FAniLY STERCORARIID^. 



Skuas and Jaegers. 



Nostrils, separate, and not tubular; bill, with cere; front toes, palmate 

 (full webbed); hind toe, small, but always present; end of upper mandible 

 (unguis), swollen, and somewhat rounded; back and wings, 

 always dark, sometimes sooty, sometimes barred with brown ; 

 tail, never white or gray, usually very dark ; middle tail feath- 

 ers, longest. The cere (hard skin=like covering on base of upper 

 mandible) will distinguish these birds from Gulls. 



* Group 1. Wing, 11 to 15 inches long. 



Underparts, not entirely pure white; bill, over 1.35; tarsus, over 1.80; middle tail 

 feathers, not pointed ; plimiagt', soiiietiuit's dark l)r()\vii; sometimes mixed graj', t)ru\vu, and 

 whit*'. Stercorarius pomarinus. Pomarine Jseger. 



See No. 10. 



Bill, under 1.35; tarsus, und<M- 1.80; middle tail feathers, pointed; base of unguis 

 to frontal feathers less than length of unguis; shafts of primaries, yt'ilow wliite. 



^-tcrcorarins longicnudus. Long=tai!ed Jfeger. 



See \o. 21. 



Bill, under 1.35; iar<u~. under l.sO; middle tail feathers, pointed ; base of unguis to 

 frontal feathers, greater than length of unguis; shaft.s of i)rimaries, ytdJowish white. 



Stercarnrius parasiticus. Parasitic Jjeger. 



See NO. 20. 



* Group 2. Wing, over 15 inches long. 



Bill, with cere; j^eueral color, dark Itrown. re or le.ss streaked with li<iht l>r()wn ; a 



l)atch ot white at base of primarie.s. Mcyalestris skua. Skua. 



See No. 18. 



• For (ilrectioiiH for iiieatiurciiionl, (^co \>nm! U. 



