188 
MAP SHOWING THE EVOLUTION OF THE 
PRESENT MIGRATION ROUTE OF THE 
GOLDEN PLOVER (SEE 
PAGE 187) 
Golden plovers in considerable numbers 
fly each fall the 2,400 miles across an 
islandless sea from Alaska to Hawaii, 
spend the winter there, and fly back 
again the next spring to nest in Alaska. 
But how did they first find their way to 
Hawaii? 
It is not to be supposed that any birds 
would deliberately strike out over un- 
known seas hunting for a new winter 
home. It is scarcely more probable that, 
even if a large flock was caught in a 
storm and carried far out of its course 
to the Hawaiian shores, the birds would 
change in a single season habits of count- 
less generations and start at once a radi- 
cally new migration route. It has already 
been said that present migration routes 
are evolutions—age-long modifications of 
other routes. ‘The problem, then, is to 
find some migration route from which 
the golden plover’s present Hawaiian- 
Alaskan route could have been easily 
and naturally derived. 
The bird breeds on the northern shores 
of eastern Siberia, from the Liakof Is- 
lands to Bering Strait, and on the Alaska 
side of the strait south to the northern 
OUR GREATEST TRAVELERS 
base of the Alaska peninsula (page 189). 
It winters on the mainland of southeast- 
ern Asia, in the eastern half of Australia, 
and throughout the islands of Oceanica, 
from Formosa and the Liu Kiu Islands 
on the northwest to the Low Archipelago 
in the southeast. 
The breeding range has an east-and- 
west extension of about 1,700 miles, 
while the winter home extends nearly 
half around the globe—i10,000 miles— 
from India to the Low Archipelago. 
Undoubtedly the original migration route 
was approximately north and south, be- 
tween the nests in Siberia and the winter 
resorts in southern Asia. In the course 
of time the species spread eastward in 
the winter to Australia, to the islands 
along the eastern coast of Asia, and 
throughout Oceanica, while at the same 
time the breeding range was extended 
eastward across Bering Strait to Alaska. 
If all these extensions took place be- 
fore there was any cutting off of corners 
in the migration route, then at this stage 
of development the Alaska-breeding birds 
were journeying over 11,000 miles (page 
189, No. 1) to reach the Low Archipel- 
ago, distant only a little more than 5,000 
miles in an air-line. 
It is fair to suppose that early in the 
course of the eastward extension among 
the Pacific islands, the plover began to 
shorten the roundabout journey by flights 
from the northern islands to eastern 
Asia, and finally to Japan (No. 2). The 
most northern island is Palmyra, and the 
flight from there westward to the nearest 
of the Marshall Islands is about 2,000 
miles; thence a 3,000-mile journey, with 
several possible rests, brings the birds to 
Japan. 
It is easily possible that birds accus- 
tomed to this 5,000-mile flight might be 
driven by storms a thousand miles out of 
their course and discover Hawaii. When 
from Hawati they attempted to reach 
Japan (No. 3) they would find a chain of 
islands stretching for 1,700 miles in the 
desired direction, and the final flight of 
2,000 miles from the last of these—the 
Midway Islands—to Japan would be no 
longer than previous flights to which they 
had become accustomed. 
Having once learned the route from 
