RICHARDSON'S SKUA 



185 



practically similar to those of the great skua, except that the latter are 

 much smaller and usually lighter in colour. 



In this species the two middle tail-feathers, which project about 

 4 inches in advance of the others, are so twisted as to cause the 

 vane to be vertical in place of horizontal. The upper-parts are umber- 

 brown inclining to sooty black on the crown ; the neck is white with a 

 few straw-coloured pointed feathers ; the breast is wholly white ; but 

 the flanks and abdomen are brown. Young birds are sooty brown 

 with rufous bars and mottlings ; and differ from those of the two next 

 species in that the shafts and much of the inner webs of the primaries 

 are white. In the adult the legs and feet are reddish black, but in 

 young birds they are mingled yellow and black. A dark phase of the 

 species is not uncommon. 



Richardson's Skua Richardson's, or, as it is often called, the Arctic skua, 



(Stereorarius ^^^^ named Larus crepidatus by Sir Joseph Banks, 



erepidatus) ^^'^^ accompanied Cook on his voyages to the South 



Seas as naturalist, and who was probably quite 



unaware that it was to be found breeding in the northern part of the 



British Islands. At a later date it was named Lcstris ricJiardsoni 



by the ornithologist Swainson, but this title only survives as the 

 popular designation of the species. An inch inferior in length to 

 Temminck's skua, the present species, as already mentioned, may be 



