396 LARIDAA 
others rich reddish-brown, usually heavily blotched with 
darker shades of brown, or they may be finely speckled or 
not marked at all. They resemble those of the Common 
Tern, but are, on an average, smaller. 
Incubation seldom becomes general before the end of the 
first week in June. As with other Terns, the males bring 
fish to feed the females when incubating. 
In defence of its young and eggs, the Arctic Tern possesses 
undaunted courage. 
Geographical distribution.—North of the British Isles, 
the breeding-range is circumpolar, and this species reaches 
far within the Arctic circle. It has been obtained above 
lat. 82° N. On migration in autumn it extends widely 
over the European, Asiatic, and African Continents, even 
to lat. 66° S., ¢.e., beyond New Zealand (Saunders). 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial—This species so closely 
resembles the Common Tern in plumage that it is only 
necessary to point out the distinguishing features. In the 
Arctic Tern the breast and abdomen are of a uniform 
‘french’ or ‘pearl’ grey, without a vinaceous tint. Chin, 
cheeks, and throat, also grey, but paler in shade; tail- 
feathers, white, edged externally with very pale grey; the 
outer feathers of the tail longer, and the grey stripe on the 
inner web of each outer primary paler and narrower thai 
in the Common Tern. 
Adult female nuptial—Similar to the male plumage; 
outer tail-feathers shorter. 
Adult winter, male and female.—Forehead and top of 
head, mottled with white; breast and abdomen, paler than 
in the nuptial plumage. 
Immature, male and female. — Forehead and top of 
head, whitish; back of head, blackish; sides of neck, 
washed with buff; back of neck, back, and wings, mottled 
and barred with buff; outer web of tail-feathers, greyish ; 
breast and abdomen, white. 
Beak. Coral-red. 
Beak. (Immature Bird.) Black (cf. Common Tern). 
FEET. Dull red. 
TrR1pDEs. Blackish-brown. 
