GOLDEN’ PLOVER. 81 
infrequently at the Bermudas, Cape Cod, and Long Island. After a 
short stop in the Antilles and northern South America, they pass to 
the winter home in Argentina and remain there from September to 
March, ss ie 
The return northward in spring is by a different route, the details 
of which are not yet determined. What is known is that they disap- 
pear from Argentina and shun the whole Atlantic coast from Brazil 
to Labrador. In March they appear in Guatemala:and Texas; April 
finds them on the prairies of the Mississippi Valley; the first of May 
sees them crossing our northern boundary; and by the first week in 
June they reappear on thein breeding grounds in the frozen north. 
Various theories have been advanced to account for this ‘strange 
migration course. The simplest explanation seems to be the applica- 
tion of the following, which may be laid down as the fundamental law 
underlying the choice of migration routes. Birds follow that route 
between the winter and summer homes that:is the shortest and at the 
same time furnishes an abundant food supply. Applying this rule to 
the case of the golden plover, the following facts are apparent: The 
plover is a bird of treeless regions; it summers on the tundras and 
winters on the pampas; an enormous food supply especially palatable 
tempts it in the fall to Labrador and furnishes power for the long 
flight to South America.. To attempt to return in spring by the same 
course would be suicidal, for at that season Labrador would furnish 
scant proverder. The plover seeks the shortest treeless route over- 
land, and alighting on the coast of Texas travels leisurely over the 
Mississippi Valley prairies, which are abundantly supplied with food, 
to the plains of'the Saskatchewan and thence to the Arctic coast.’ 
Spring migration.—The principal line of migration.from the winter 
home northward, through South America is not yet known; the 
species is said to be common in March and April in Peru (Sclater and 
Salvin) east of the mountains, but next to nothing is known regarding 
its appearance in the territory for a thousand miles to the northward. 
The species is practically unrecorded at all seasons of the year from 
Ecuador, Colombia, Panama, Nicaragua, and Honduras, and though 
a few have: been noted in Costa Rica (Cherrie), Guatemala (Sclater 
and Salvin),.and eastern Mexico (Sclater), in none of these countries 
have the great flocks been seen that are so characteristic of the fall 
flight in the Lesser Antilles and of the spring advance up the Missis- 
sippi Valley. Not until Texas is reached can the movements of the 
golden plover be definitely traced, and at no place between Peru and 
Texas has it ever been recorded as common. In fact, the records as 
they stand are what they should be if the plover escapes the forested 
regions of northern South America and Central America by a single 
flight of from 2,000 to 2,500 miles from the valleys of eastern Peru to 
the treeless prairies of Texas. The general time of appearance in the 
36595°—Bull. 35—12——6 
