120 BRITISH BIRDS. WITH THEIR NESTS AND EGGS. 



Here they are abundant, several pairs being generally found in pretty close 

 proximity, and very often establishing themselves amongst a colony of Gulls, with 

 whom they live peaceably enough at their breeding stations " (Buckley and Harvie- 

 Brown). In Shetland the islands of Noss and Mousa are the Skua's chief rendezvous. 

 The Shetlanders call the bird Shooi. In Caithness it used to breed abundantly 

 on the wide moors and marshy tracts of the interior of the county ; but the bird 

 has been, within recent times, almost exterminated by game-keepers. One pair 

 breeds in the same spot every year. The Hebrides is also among this bird's 

 nurseries where it goes by the name of Fasgadair. It breeds on Stuala Island, 

 Uist ; in Tyree ; in the Inner Hebrides there are " certainly two large scattered 

 colonies of Richardson's Skuas nesting, one of which may consist of over one 



hundred pairs scattered over a large area" (Harvie-Brown and Buckley). 



As already mentioned it breeds, as it has done for Over a century, in Jura which 

 is the southern limit of its range. 



It breeds in all the arctic and sub-arctic regions of both the eastern and the 

 western hemispheres. In winter it ranges south along the coasts of Africa down 

 to the Cape, and from Eastern Asia down to Australasia, and along the Atlantic 

 coasts of America south to Rio de Janeiro. 



Like the Potnatorhine Skua, the present species has two phases of plumage, 

 one entirely umber-brown, and the other brown on the upper side and white on 

 the breast, with brown bars on the sides and chest, and this in both sexes 

 more or less persistently throughout life. The males and females of both phases 

 resemble each other. 



The pale-breasted adult, in breeding plumage, has " the feathers at the base 

 of the bill dull white ; forehead and lores ash-brown ; crown and occiput darker 

 brown ; hind neck dull white, shading into ash-brown on the shoulders, and thickly 

 streaked with golden straw-colour ; mantle, wings, tail-coverts and tail-quills darker 

 brown; the secondaries blackish; the shafts of the principal primaries white, 

 under tail-coverts, abdomen and under wing ash-brown ; bfeast and chin dull 

 white ; throat and sides of the neck whitish, streaked with straw-yellow ; bill 

 brownish horn colour, darker in front of the cere ; tarsi and toes black" (Saunders). 



The dark coloured adult is similar to the light breasted form, but is "washed 

 with sooty throughout, the under parts being nearly as dark as the mantle, which 

 is of a deeper tone than in the pale breasted form ; the acuminate feathers of the 

 neck yellow, but not so strongly contrasted; bill rather blacker" (Saunders). 

 Length 21$ inches; wing 13$; tail 5!, and to the end of the elongated feathers 

 9 the elongation of the central feathers of the tail is one of the characters which 

 separate Stercorarius from Megalestris ; tarsus if; middle toe, with its claw, it 



