ARCTIC TERN. 
221 
The peculiar distribution of this species, and the supposition that 
the flocks never migrate down the shores of the Pacific, have led 
some naturalists to suggest that the birds were originally confined 
to the Atlantic Ocean, though ranging on both its eastern and west- 
ern shores. The breeding area, they say, was gradually extended 
east and west, one division of the birds going off along the north- 
ern shore of America, the other across the end of Europe and 
Asia, advanced flocks of each division finally meeting at Bering 
Sea. But at the approach of winter these flocks separated at that 
point, and ignoring the Pacific route to a milder climate, they fol- 
lowed “ hereditary instincts ” and returned to the Atlantic, each 
division migrating along its own path and wintering on its own 
chosen shore, — the flocks of one wing ranging to the Middle 
States, the others to the Canary Islands. 
The hypothesis is interesting and the facts are in the main cor- 
rect; but it has been strongly hinted that the hypothesis has been 
cruelly disturbed by the birds themselves, — they have turned up in 
California. The hypothesis should not, however, Ije abandoned 
because a few individuals have forsaken the traditions of their 
race, — that is a common weakness of those who “go west.” 
Enough Arctic Terns still follow the ways of their fathers when 
migrating, to prove the strength of this inherited tendency. 
In habits as well as in general appearance and manners this 
species differs but slightly from the Common Tern. Our bird is 
perhaps more graceful on the wing, though both fly with wonderful 
grace and ease, and the Arctic Tern displays more boldness in 
defence of its young or of a wounded companion. It seems utterly 
fearless, and will advance so clo.se as to strike with its pinions a 
hand that menaces its young ; and when a colony is invaded by 
any marauder, the Arctic Tern is the first to lead an attack upon 
the intruder, and the attack is so fierce that the colony is usually 
saved. 
The Arctic Terns frequent rocky islands and secluded portions 
of the mainland, and in these localities the birds gather in large 
communities, They may be seen sitting on a rock or stump, watch- 
ing for their prey, in Kingfisher fashion. They float buoyantly on 
the water, but rarely dive beneath the surface. 
