LARUS STERCORARIUS 839 



the outer web, the rest grey at the base and tipped with white ; bill yellow, 

 red at the angle of the lower mandible ; legs and feet light flesh-colour ; 

 iris clear grey. Culmen 2'7, wing 17*0, tail 7'9, tarsus 2'6 inch. 



Hob. The coasts of the North Pacific and Bering's Sea ; 

 Kamchatka ; the Aleutian and Commander Islands ; in winter 

 south to Japan and California. 



In habits it resembles L. glaucus. It breeds abundantly on 

 Bering and Copper Islands, frequently on isolated rocks and 

 small islands, or on the ledges of rugged cliffs overhanging the 

 sea, the nest being a depression, lined with dry grass, and early 

 in July, 2 to 3 eggs are deposited, which resemble those of 

 L. glaucus, but are somewhat smaller, greener, and more boldly 

 spotted. 



STERCORARIUS. Briss., 1760. 



1154. GREAT SKUA. 

 STERCORARIUS CATARRHACTES. 



Stercorarius catarrhactes (Linn.), Syst. Nat. i. p. 226 (1766) ; (NaumJ, 

 x. p. 470, Taf. 270 ; (Hewitson), ii. p. 505, pi. xlii. ; (Gould), B. 

 of E. v. pi. 439 ; (id.), B. of Gt. Brit. v. pi. 78 ; Dresser, viii. 

 p. 457, pi. 609 : (Saunders), Cat. B. Br. Mus. xxv. p. 315 ; (id.), 

 Manual, p. 687 ; (Lilford), vi. p. 69, pi. 31 ; Cataracta sleua, Ketz. 

 Faun. Suec. p. 161 (1800) ; Kidgway, p. 21. 



Labbe cataracte, French ; Gt^osse JRaubmowe, German ; Groote 

 Jager, Dutch ; Havskumur, Hakallaslmmur, Icel. ; Stor-Kjove, 

 Dan. ; Skua, Storjo, Norweg. ; Storlabl, Swed. 



ad. (Fseroes). General coloration dark brown marked with yellowish 

 red ; crown, rump, and upper tail- coverts almost uniform dark brown, the 

 feathers on the rest of the upper parts with rufous or rusty yellowish tips ; 

 basal half of primaries white forming an alar patch ; tail blackish brown, 

 marked with white at the extreme base ; throat feathers with yellowish 

 shaft markings ; abdomen tinged, and flanks slightly marked with rufous ; 

 bill black, paler at the base ; legs and feet blackish ; iris dark brown. 

 Culmen 2 - 4, wing 15'6, tail 7'0, tarsus 2'7 inch. Sexes alike. The young 

 bird is more distinctly marked with yellowish, and has more white on the 

 wings and tail. 



Hob. Iceland, the Faroes, and Shetlands in summer ; rarer in 

 South Greenland; scarce in Scandinavia; in winter south to 

 the Straits of Gibraltar ; a rare straggler to Germany, Switzer- 

 land, N. Italy, and the Mediterranean. 



Essentially predatory in its habits the Skua seldom takes 

 the trouble to fish for itself, but despoils the Gulls of their 



