THE MIGRATION OF NORTH AMERICAN BIRDS 2) 
miles away. Such seasonal flights are exceeded in length, however, 
by the journeys of several species of water birds, chiefly members of 
the suborder of shore birds. In this group are 19 species that breed 
north of the Arctic Circle and winter in South America, 6 of them 
going as far south as Patagonia, and thus having a migration route 
more than 8,000 miles in length. 
The arctic tern (Sterna paradisaea) is the champion ‘‘globe trotter”’ 
and long-distance flier (figs. 14 and 15). Its name “arctic” is well 
earned, as its breeding range is circumpolar and it nests as far north 
as it can find a suitable place. The first nest to be found in this 
region was only 74° from the North Pole, and it contained a downy 
chick surrounded by a wall of newly-fallen snow that had been scooped 
out by the parent. 
In North America it 
breeds south in the in- 
terior to Great Slave 
Lake, and on the At- 
lantic coast to Mas- 
sachusetts. After the 
young are grown, the 
arctic terns disappear 
from their North 
American breeding 
grounds, and a few 
months later they 
may be found in the 
Antarctic region, 
11,000 miles away. 
Until very recently 
the route followed by 
these hardy fliers was 
a complete mystery, 
for although a few 
scattered individuals 
have been noted south 
as far as Long Island, 
the species is other- 
wise practically un- wae: 
known along the At- Figure 14.—Arctic tern. The longest flight known for _ indi- 
antie coasts of North vidual bird was accomplished by an arctic tern thatin 3 months 
: flew from the coast of Labrador to the coast of southeastern - 
America and South § Atrica. 
America. It is, how- 
ever, known as a migrant on the west coast of Kurope and Africa. 
By means of numbered bands the picture is now developing of what 
is apparently not only the longest but also one of the most remarkable 
of all migratory journeys. 
Judging by the evidence at present available, it seems likely that 
the arctic terns of eastern North America originally found their way 
here from the Old World, probably by way of Iceland and Greenland. 
Consequently when the time comes for them to migrate to winter 
quarters they do not go directly south as do the common (Sterna 
hirundo) and Forster’s terns (S. forster), but instead, they fly back 
eastward along their ancestral route across the Atlantic to the shores 
of Europe and then go south along the African coast to their winter 
home; those that breed in the northwestern part of the continent, as 
