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. 



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 their 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 provender. 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 fail 

 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 

 52928°— Bull. 35—10 6 



