46 ROUTES OF MIGRATION 
Most birds appear to return to their summer homes over much the 
same route by which they left them. There are, however, a few marked 
exceptions to this rule. Among our land-birds, the Connecticut War- 
bler enters the United States through Florida and journeys thence 
northwestward along the Alleghanies, and west to Missouri, to the 
Upper Mississippi Valley and Manitoba. At this season it is unknown. 
on the Atlantic Coast north of Florida; but during its return migration, 
in September and October, it is often not uncommon from Massachu- 
setts southward and, at this season, is rare or unknown in the Missis- 
sippi Valley south of Chicago. (See Cooke, ’04.) 
Among our water-birds, cases of this kind are more frequent. The 
fall migration often brings to the Atlantic Coast species which are 
rarely if ever seen there in the spring. The Black Tern, for example, 
occurs near New York City in numbers, from August to October, but 
is not found there in the spring. 
The Golden Plover, as has been shown by Cooke (’93), after breed- 
ing in June on the shores of the Arctic Ocean, in August migrates 
southeastward to Labrador, where it feeds on the crowberry (Em- 
petrum), laying on a supply of fat as fuel for the remarkable voyage 
which follows. From Labrador the birds fly south to Nova Scotia 
and thence lay their course for northern South America in a direct 
line across the Atlantic. 
Under favorable conditions they may pass the Bermudas without 
stopping, but should they encounter storms they rest in these islands 
and are also driven to our coast. Their first stop may be made in 
the Lesser Antilles, through or over which they proceed to South 
America, en route to their winter quarters in southwestern Brazil and 
the La Plata region. 
In returning to their Arctic home these Plover pass northward 
through Central America and the Mississippi Valley, the main line 
of their fall and spring routes, therefore, being separated by as much as 
1,500 miles. 
The explanations advanced to account for the gradual develop- 
ment of migration routes, over which birds in the fall retrace the path 
followed in the spring, are inadequate to account for the origin of 
these phenomenal journeys, on which the pioneer voyagers must 
apparantly have embarked unguided by either inherited or acquired 
experience. Nor do we understand how birds have learned to cross 
regularly over bodies of water, hundreds or even thousands of miles 
in width. 
European birds cross the Mediterranean, to and from Africa, at 
a point where soundings indicate that a much closer land relation 
formerly existed; but the 400-mile flight from Jamaica to northern 
South America, the 600-mile flight from the nearest land to the Ber- 
mudas, or the journey regularly made by the Turnstone and Golden 
Plover to Hawaii, 2,000 miles from the nearest land, are evidently 
not to be explained in this way. 
