488 POMARINE SKUA. 



foundland and Labrador, and never, so far as I can learn, extending its range to our New 

 England shores. This Gull is described as inhabiting the open ocean and feeding upon the 

 blubber of whales, walruses, etc., keeping on the edge of the ice in winter, which thus lim- 

 its its southern range. 



GENUS VIII. STERCORAR1US. THE SKUAS. 



GEN. CH. Bill, strony and curved at tip, with nostrils linear. Central tail feathers , projecting. Tarsus and feet, stout. 

 Members of this genus are usually dark in color. There are three species with-in our limits. 



STERCORAKIUS POMATORHINUS. 



Pomarine Skua. 

 Slercorarius pomatorhinus VIEILI,., Nov. Diet.; 1819, 158. 



DESCRIPTION. 



SP. CH. Form, robust. Size, large. Bill, stout. Central tail feathers, rounded at tip and projecting about three in- 

 ches. Color. Adult. Above and on under tail coverts, dark-brown. Beneath, white. Sides of neck, pale yellow. Iris, 

 brown, bill, greenish, and feet, black. Youny. Sooty-brown throughout, sometimes quite dark, but generally with the 

 feathers edged with whitish and rufous. Central tail feathers, short. 



OBSERVATIONS. 



In some intermediate stages of plumage, there is a band of spots, of greater or less width, across breast. Known by 

 the large size, the wing being at least one inch longer than that of the preceding species, and the rounded tips to elonga- 

 ted central tail feathers. Distributed in summer throughout the Arctic Regions; wintering as far south as New Jersey. 

 DIMENSIONS. Length, -20-00; stretch, 48'00; wing, 13'50; tail, 8'50; bill, 1'75: tarsus, 2-00. 



HABITS. 



The Poinarine Skua breeds in high, northern latitudes, only coming south during au- 

 tumn and winter. Like all the Skuas, they are parasitical in habit, pursuing Gulls and 

 Terns in order to force them to drop their prey, which is snatched up by the Skuas before 

 it reaches the water. The Pomarine Skuas are very shy birds and keep well out to sea. 



STERCORARIUS CREPIDATUS. 



Richardson's Skua. 

 Stercorarius crepidatus VEILL., Nov. Die.; 1819, 155. 



DESCRIPTION. 



SP. CH. Form, robust. Size, rather small. Bill, rather slender. Central tail feathers, acutely pointed at tip and pro- 

 jecting about four inches. COLOR. Adult. Above and under tail coverts, dark sooty-brown with a slaty tinge, and be- 

 coming bluish on wings and tail. Sides of neck, pale yellow. White beneath. Iris, brown, bill, yellowish and feet, black. 

 Young. Dusky brown throughout, sometimes very dark but usually with the feathers edged with whitish and rufous. 

 The central tail feathers are short. DIMENSIONS; length, 21-00; stretch, 45-00; wing, 12-00; tail,8'50; bill, 1-_30; tarsus, 1-75. 



OBSERVATIONS. 



Known from the preceding species by the smaller size, the wing measuring only about twelve inches in length; and 

 from the succeeding, when adult, by the shorter central tail feathers; and in young by the shaft of all the primaries being 

 mostly white. This species passes though many variations between the young and adult. 



DESCRIPTION OF NESTS AND EGGS, 



Eyys, placed on the ground, two or three in number, oval in form, deep yellowish or greenish-brown in color, spotted 

 and blotched with brown and uiubur of varying shades. Dimensions from 1-53 x 2'12 to 1 '60x2-35. 



HABITS. 



Richardson's Skua is much more common than any of the genus which occur with us, 

 frequenting the bays and harbor mouths, where it may often be seen in pursuit of Gulls, a 

 habit which has earned for it the name of Gull Chaser. Although very shy when with us 

 in autumn, Mr. Howard Saunders writes me, that he found them so tame on their breeding 

 grounds on the Shetlands, that they frequently struck his head in their downward swoops, 



sTERCORAnras BTTPPONI. 



Buflbn's Skua. 

 Sierairarius BuffoniCuvts., Pr. Phil. Acad. ; 1863, 136. 



DESCRIPTION. 



Sr.Cn. Form, rather slender. Size, small. Central tail feathers, long and slender, projecting from eight to ten ini-h- 



