BIRDS OF THE BRITISH ISLES. 355 



IRicbarbson'0 Sfcua, 



RICHARDSON'S Skua (Stercorarius Richardsoni, Swainson) 

 is one of our summer migrants. It inhabits both the 

 Northern Palearctic Region and the Nearctic Region. 

 The adult has the upper parts mostly of a slaty-grey ; neck, 

 tinged with yellowish-buff; beneath, white; sides of belly, 

 lower portion of latter, and under tail-coverts, tinged with 

 brownish-grey; central tail-feathers, elongated and reaching 

 considerably beyond the ends of wing quills, the latter 

 having white shafts at all ages; irides, hazel; bill, greyish; 

 tip, black; legs and feet, black. Length, from twenty to 

 twenty-one inches. The female is similar to the male, but 

 the two central rectrices are not so long. The young after 

 the first moult have the basal half of feet yellow. 



