The Skuas. 
209 
The only difference of importance between the Great Skua 
THE an d the three smaller species which follow consists in the 
POM A TORHINE elongation of the centre tail-feathers. The Pomatorhine Skua is 
v the largest of the three, and the middle tail feathers project for 
(Stercoranus 0 
THE 
POMATORHINE 
SKUA. 
( Stercorarius 

about four inches beyond the others, and are vertically twisted. 
It is not so active a bird as Richardson's or Buffon’s Skua, and 
is generally said to be less brave than those two birds. I'he present species breeds in 
the tundra of the Arctic Re- 
gions of both Hemispheres, 
and only visits Great Biitain 
in winter. The nests are 
simply depressions in the 
moss, and the eggs are of 
the usual dark brown type 
of those of Skuas, being deep 
clay-brown or olive-brown, 
with reddish or blackish- 
brown spots. They measure 
is scarcely known, but in parts of Norway and in the north of Scotland, both light 
and dark forms occur nearly in equal numbers, and often pair together. Richardson’s 
Skua is a very active and agile bird, and harries the Terns and small Gulls to make 
them disgorge their prey. For this reason they are not loved by their relations, and 
are regarded with suspicion by other species, whose eggs they will try to carry 
off. I have seen the normally peaceful Oyster-catcher attack one of these Skuas 
and give it such a buffeting that it was glad at last to clear oft'. The nest is a 
depression in the moss on the summit of a low island, and the eggs, two in 
number, are dark chocolate, with brown or blackish spots, grey underlying 
spots being also distinct. The length is from two inches-and-a quarter to two 
inches-and-a-half. 
about two inches-and-a-half 
to two inches - and - three - 
quarters in length. 
The Pomatorhine Skua. 
RICHARDSON’S 
SKUA. 
( Stercorarius 
crop id ci lus.) 
This species has the centre tail-feathers long and tapering, 
and projecting quite three inches beyond the others. It has two 
phases, which are white-breasted or sooty-breasted in colour, and 
the latter is generally considered to be a melanistic phase of the 
white-breasted form. In the high north the dark-coloured bird 
BUFFON’S SKUA. 
( Stercorarius 
parasiticus.) 
Very similar to the preceding species, but always much 
greyer in appearance, and further distinguished by the length of 
the centre tail-feathers which sometimes attain the length of nine 
inches : only the two outer primary quills have white shafts. 
