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 young 
6'. pomatorhinus 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 w'ell 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 
wunter 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 Kooks in a dry season, and may be constantly seen 
quartering the tundra for eggs or young. I should be inclined 
to estiriiate 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 
mghteen 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 
