466 STERCORARIIDAL 
of Arctic Europe,! Asia, and America: unlike the Arctic 
Skua, it is only a visitor to the Faroes and Iceland. Its 
migratory range in winter extends to Southern Europe, 
and to latitude 40° N. on the Atlantic side of America, and 
20° N. on the Pacific side. 
DESCRIPTIVE CHARACTERS. 
PLUMAGE.” Adult male nuptial.—'Top of head, upper 
half of cheeks, and back of neck, brownish-black; lower 
cheeks and rest of neck, buffish-yellow ; back, scapulars, and 
long central tail-feathers, of a greyer shade than those of 
the Arctic Skua; wings (including primaries), and lateral 
tail-feathers, dark brown; lower throat and breast, white ; 
abdomen, greyish-brown. 
Adult female nuptial.—Similar to the male plumage, but 
the central tail-feathers are shorter. 
Adult winter, male and female.—Similar to the nuptial 
plumage, but with a tendency to striations on the flanks, 
and on the upper and under tail-coverts, in birds not quite 
mature. 
Immature, male and female.—Barred on the back, wings, 
breast, abdomen, and tail-coverts, with greyish-brown and 
white. The young of the first year vary in tint, especially 
about the abdomen. They are greyer and less rufous than 
examples of the Arctic Skua. The readiest distinction 
between the two species at any age is to be found in the 
shafts of the primaries. Thus in the Arctic Skua these are 
all white, whereas in the Long-tailed Skua they are all 
brownish save the two outer on either side (Saunders). 
Beak. Dark horn-colour. 
Fret. Greenish-grey; toes black ; webs of young, parti- 
coloured, being darker near their extremities.® 
IrmpDeEs. Dark brown. 
' Breeds abundantly during some seasons on the Fells of Lapland, 
where it preys mainly on Lemmings. 
2 In the ‘Ibis’ for 1865, p. 217, Professor Newton describes an 
instance of dimorphism in this species, though normally it is very much 
less marked than in the last-named bird. 
3 The webs in the young of the Arctic and of the Pomatorhine Skuas 
are also parti-coloured. 
