TWIST-TAILED OR POMATORHINE SKUA 289 



it will attack the Eagle if he approaches their nests is a fact I have 

 witnessed : I once saw a pair completely beat off a large Eagle 

 from their breeding-place, on Rona's Hill. The flight of the Skua 

 is stronger and more rapid than that of any other Gull. It is a 

 great favourite with the fishermen, frequently accompanying their 

 boats to the fishing-ground, or Haaf, which they consider a lucky 

 omen ; and in return for its attendance, they give it the refuse of 

 the fish which are caught. The Skua Gull does not associate in 

 groups ; and it is seldom that more than a pair are seen together. 

 During the breeding season it is highly courageou ■ ; and will strike 

 furiously at, and will even pursue, any one who may happen to 

 approach its nest, which is constructed among the heath or moss ; 

 the female laying two eggs." 



Some authors state that the Common Skua obtains its livelihood 

 by levying contributions on the White Gulls, compelling them to 

 disgorge their prey, and catching it before it reaches the water ; 

 but Dr. Edmonston, who had great opportunities of watching the 

 habits of these birds, says that they do not adopt the practices 

 correctly attributed to the Arctic Gull, or Richardson's Skua. The 

 voice of the Common Skua is said to resemble that of a young Gull, 

 being sharp and shrill ; and it is from the resemblance of its cry 

 to that of the word Skua, or Skui, that it obtains its popular name. 

 That it is remarkably courageous and daring, all accounts agree. 

 Mr. Low says that, when the inhabitants are looking after their 

 sheep on the hUls, the Skua often attacks them in such a manner 

 that they are obliged to defend themselves with their cudgels held 

 above their heads, on which it often kills itself ; and Captain Vetch, 

 in the Memoirs of the Wernerian Society, says that it not only 

 drives away Ravens and Eagles, but that the larger quadrupeds, 

 such as horses and sheep, which venture near its nest, are imme- 

 diately put to flight. Its northern name is Bonxie. 



TWIST-TAILED OR POMATORHINE SKUA 



STERCORARIUS POMATORHINUS 



Upper plumage uniform dark brown ; feathers of the nape long, tapering 

 lustrous ; sides of the face and under plumage white ; a collar of brown 

 spots on the breast, and similar spots on the flanks ; shafts of the quills 

 and tail-feathers white, except at the tip ; two central tail-feathers 

 projecting three inches, not tapering ; tarsus two inches long, rough at 

 the back, with projecting scales. Length twenty-one inches. Young 

 birds — upper plumage dusky brown, mottled with reddish yellow ; 

 under, yellowish white, thickly set with brown spots and bars. Eggs 

 ash-green, spotted with dusky. 



The habits of this bird vary but little from those of the other species. 

 Its home is in the Arctic seas, from which it strays southwards in 

 winter, and has been occasionally seen on our coasts. The foUow- 



B.B. U 



