RICHARDSON S SKUA. 99 



From S. parasiticus^ the present species is distinguished by 

 its comparatively longer bill and by the white shafts to the 

 primaries, whereas S. parasiticus has only the two outer prima- 

 ries white-shafted. The young birds can be told from you.ig 

 S. pomatorJiiims by their smaller size, but it is difficult to 

 distinguish the young of 6*. crepidatus and S. parasiticus. 



Range in Great Britain. — Richardson's Skua breeds in the 

 Shetland and Orkney Islands, as well as in Sutherland and 

 Caithness, whilst it is also found nesting in the Hebrides. 

 During migration it occurs on both the Scottish coasts, but 

 more frequently occurs on the east coast of England than on 

 the west coast. It also visits Ireland at intervals. 



Range outside the British Islands. — The present species breeds 

 throughout the Arctic and sub-Arctic regions of both hemi- 

 spheres, its Scottish habitat constituting its southern limit. In 

 winter Richardson's Skua extends its range to the southern 

 oceans, having been recorded from the Cape of Good Hope, 

 the shores of the Persian Gulf, the Indian Ocean, and as far 

 as Australia and New Zealand, while it has also been noted 

 from as far south as Rio de Janeiro in South America. 



Hahits. — The habits of all the Skuas, or Jaegers, as they are 

 called by American naturalists, are very much the same. The 

 following account of Richardson's Skua on the island of 

 Kolguev has been published by Mr. A. Trevor-Battye : — 



" Although greatly dependent when at sea upon the labours 

 of other Gulls, the breeding pairs are as persistent robbers of 

 eggs as Rooks in a dry season, and may be constantly seen 

 quartering the tundra for eggs or young. I should be inclined 

 to estimate that of breeding birds on Kolguev there is about 

 one pair to every seven square miles of country. We never 

 found a colony, nor even two pairs together. All those I saw 

 belonged to the light-coloured race. On June 29 w^e took 

 eggs about incubated. A nest containing one egg (July 7), 

 was a simple depression in dry grass : the egg had a remarkable 

 escape. We were driving along — four sleighs, which meant 

 eighteen reindeer — when I called out to my companion 

 Hyland, who was in front, to stop ; for, some thirty yards or 

 so away, a pair of Skuas were behaving as though they had a 

 nest. However, we could make nothing of it, and had just 



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