JAEGERS AND SKUAS. (55 



ORDER LONGIPENNES. LONG-WINGED SWIMMERS. 



FAMILY STERCORARIID^. JAEGERS AND SKUAS. 



Two of the six known members of this family are found in the 

 antarctic regions, while the remaining four inhabit the northern parts 

 of the northern hemisphere. Except during the nesting season, the 

 Jaegers are as a rule pelagic, though they sometimes visit large bodies 

 of water inland. They generally obtain their food by robbing Gulls 

 and Terns, and have been well named the Hawks of the sea. Their 

 greater power of flight enables them to successfully pursue these birds 

 and force them to disgorge their recently captured prey. 



KEY TO THE SPECIES. 



A. Bill over 1-35; tarsus over 1-70 ; middle tail-feathers never pointed. 



a. Bill over 1-90 35. SKUA. 



b. Bill under 1-90 36. POMAEINE JAEGER. 



_Z?. Bill under 1-35; tarsus under 1 - 70 ; middle tail-feathers generally pointed. 



a. Scaly shield on the bill longer than the distance from its end to the tip 

 of the bill 37. PARASITIC JAEGER. 



b. Scaly shield on the bill shorter than the distance from its end to the tip 

 of the bill 38. LONG-TAILED JAEGER. 



35. Megalestris skua (Erunn.}. SKUA. Ad. Upper parts, tail, and 

 wings dark, dirty brown ; shafts of the wing and tail-feathers white, except 

 at the tip ; outer wing-feathers with inner vanes white at the base ; under parts 



somewhat lighter; neck more or less streaked with whitish. Im. "Similar 



to adult, but more distinctly streaked with yellowish, especially on the head 

 and neck." L., 22-00 ; W., 15-91 ; Tar., 2-63 ; B., 2'06 (Kidgw.). 



Range. " Coast and islands of the North Atlantic, chiefly northward. 

 Sout*h to Spain and Massachusetts. Apparently rare off the coast of North 

 America" (A. 0. U.). 



Long Island, A. V., one record. 



JV', on rocky cliffs. Eggs, two, pale olive-brown or greenish gray spot- 

 te<4 with chocolate, 2-80 x 1-90. 



36. Stercorarius pomarinus ( Ternm.}. POMARINE JAEGER. Ad., 



light phase. Vary similar in color to corresponding phase of 8. parasiticus, 

 but with the upper parts darker, nearly black. Ad., dark phase and Im 

 Similar in color to corresponding stages of 8. parasiticus. L., 22-00 ; W., 

 13-50 ; T., Ad., 8-00, Im., 5-40 ; Tar., 2-00 ; B., 1-55. 



Remarks. This species is to be distinguished from the two following bj 

 its larger size and the rounded ends of its central tail-feathers. 



Range." Kcsiclent during the summer in high northern latitudes, chiefly 

 within the Arctic Circle, and extending from Siberia in eastern Asia entirely 

 around the zone " (B., B., and R.). Migrates southward along the Atlantic 

 6 



