ARCTIC TERN 393 
scapulars, and wing-coverts, barred and mottled with ash- 
brown ; outer web of tail-feathers, grey ; inner web, white ; 
breast and abdomen, milk-white. 
Beak. Orange-red with brownish-black tip. 
Break. (Immature Bird.) Reddish-yellow with dark 
brown tips (cf. Arctic Tern). 
FEET. Deep red. 
IriwEs. Blackish-brown. 
AVERAGE MEASUREMENTS. 
TOTAL LENGTH 14°25 in 
WING Osa Wie 
BEAK oe ala eee 
TARSO-METATARSUS Osa". 
Eae yell uak 
ARCTIC TERN. Sterna macrwra (Naumann). 
Coloured Figures—Gould, ‘ Birds of Great Britain,’ vol. v, pl. 
72; Dresser, ‘Birds of Europe,’ vol. viii, pl. 579; Lilford. 
‘Coloured Figures,’ vol. vi, pl. 9. 
In its habits and plumage this greatly resembles the 
preceding species, though differing considerably in dis- 
tribution over the British Isles. The northern range of 
the Common Tern overlaps that of the Arctic; this is 
well seen about the latitude of the Northumberland and 
Lancashire coasts, where, as on the Farne and Walney' 
Islands, both species freely breed in company. 
Proceeding southward, this species diminishes’ as the 
Common Tern increases; northward, the Arctic predomi- 
nates ; above the latitude of the Moray Firth and the Island 
of Skye the Common Tern is much reduced in numbers. 
' On Walney Island, the Common Tern appears to be the more 
numerous species. 
2 Small numbers of Arctic Terns are to be found breeding as far 
south as the Scilly Isles. 
