THE ARCTIC SKUA. 783 



etc. Has been seen to chase and kill a Phalarope, and is destructive 

 to young birds and eggs of other species. 



Distribution. — British Isles. — Passage-migrant and winter- visitor. 

 Tolerably regular autumn passage-migrant, especially east coast 

 England, less regular east coast Scotland, and still scarcer south and 

 west coasts Great Britain and coasts Ireland. Periodically great 

 numbers (e.g. autumn, 1879, 1880, 1886, 1892, 1901 Great Britain, 

 and Oct., 1862, Ireland). Sometimes stops winter, but rare on 

 spring -passage except seas of 0. Hebrides, where recorded as fre- 

 quent in some years. Said to have bred but no proof. Sometimes 

 inland. 



Distribution. — Abroad. — Arctic regions north of about 70°. 

 testing proved Novaya Zemlia, islands and coast of Siberia, 

 Greenland, Point Barrow in Alaska. In winter southwards to 

 Australia, south-west Africa, New Jersey, California, Galapagos 

 Islands, and Peru. 



STERCORARIUS PARASITICUS * 



463. Stercorarius parasiticus (L.)— THE ARCTIC SKUA. 



Larus parasiticus Linnaeus, Syst. Nat., eel. x, i, p. 136 (1758 — Europe, 

 America, Asia. Restricted typical locality : coast of Sweden). 

 Stercorarius crepidatus (Gmelin), Yarrell, in, p. 674 ; Saunders, p. 691. 



Description. — Adult male and female. Summer. — Dark form. — 

 Whole upper-parts dark umber -brown, but crown down to eyes and 

 nape blacker forming ill-defined cap (all feathers with whitish bases) ; 

 feathers of sides and back of neck slightly pointed and usually with 

 central streaks of straw-yellow but sometimes these are absent ; 

 cheeks and ear-coverts with varying amount of straw-yellow, 

 sometimes none ; whole under-parts uniform sooty-brown with 

 more or less greyish tinge (bases of feathers white). Pale form. — 

 Upper -parts as dark form but blackish cap usually cut off by 

 somewhat pointed, whitish-yellow feathers of ear-coverts and sides 

 and back of neck forming a collar but this is often broken in centre 

 by umber feathers with yellow tips ; under-parts white but sides 

 of upper-breast, flanks and vent and under tail-coverts as well as 

 lores and extending slightly under eyes greyish sooty-brown, and 

 often a varying amount of pale brown across upper-breast and on 

 throat and sometimes some on rest of under-parts ; tail in both 

 forms blackish umber-brown, extreme (concealed) base white ; 

 primaries and secondaries in both forms umber-brown, tips blackish, 

 extreme (concealed) bases white but in pale form showing greyish- 

 white beyond coverts on under-surface, shafts of two outer primaries 



* Gray, Dresser, Saunders, and (following these authorities) other British 

 and Continental ornithologists, have shifted the name parasiticus frcm this 

 species to the Long-tailed Skua. In this case the change is not justifiable, as 

 fully explained by Stejneger (Proc. U.S. Nat. Museum, v, pp. 40-42), whote 

 view has now been generally accepted. — E.H. 



