Page:Condor6(5).djvu/9

Sept., 1904 there through the winter. Only adventurers out of some six species gain the South American mainland by completing the island chain. The reason seems not far to seek—scarcity of food. The total area of all the West Indies east of Porto Rico is a little less than that of Rhode Island. Should a small proportion only of the leathered inhabitants of the eastern part of the United States select this route, not even the luxuriant fauna and flora of the Tropics could supply their needs.

A still more direct route, but one requiring longer single flights, stretches from Florida to South America via Cuba and Jamaica. The 150 miles between Florida and Cuba are crossed by tens of thousands of birds of some sixty different species. About half the species take the next flight of ninety miles to the beautiful Jamaican mountains. Here a 500-mile stretch of islandless ocean confronts them, and scarcely a third of their number leave the forest-clad hills for the unseen beyond. Chief among these dauntless voyagers is the bobolink, fresh from despoiling the Carolina rice fields, waxed fat from his gormandizing, and so surcharged with energy that the 500-mile flight to South America on the way to the waving pampas of southern Brazil seems a small hardship. Indeed, many bobolinks appear to scorn the Jamaican resting point and to compass in a single flight the 700 miles from Cuba to South America. With the bobolink is an incongruous company of traveling companions—a vireo, a kingbird, and a night-hawk that summer in Florida; the queer chuck-will's-widow of the Gulf States; the New England cuckoos; the trim Alice thrush from Quebec; the cosmopolitan bank swallow from frozen Labrador, and the black poll warbler from far-off Alaska. But the bobolinks so far outnumber all the rest of the motley crew that the passage across the Caribbean Sea from Cuba to South America may with propriety be called the "bobolink route." Occasionally a mellow-voiced wood thrush joins the assemblage, or a green-gold tanager which will prepare in the winter home its next summer livery of flaming scarlet. But the "bobolink route" as a whole is not popular with other birds, and the many that traverse it are but a fraction of the thousands of North American birds that spend the winter holiday in South America.

The main traveled highway is that which stretches from northwestern Florida across the Gulf, continuing the southwest direction which most of the birds of the Atlantic coast follow in passing to Florida. A larger or smaller proportion of nearly all the species bound for South America take this roundabout course, quite regardless of the 700-mile flight over the Gulf of Mexico. It might seem more natural for the birds to make a leisurely trip along the Florida coast, take a short flight to Cuba, and thence a still shorter one of less than 100 miles to Yucatan—a route only a little longer and with much less of exposure. Indeed, the earlier naturalists, finding the same species both in Florida and in Yucatan, took this probable route for granted, and for years it has been noted in ornithological literature as one of the principal migration highways of North American birds. As a fact it is almost deserted except by a few swallows, some shore birds, and an occasional land bird storm-driven from its intended course, while over the Gulf route, night after night, for nearly eight months in the year, myriads of hardy migrants wing their way through the darkness toward an unseen destination.

West of the Florida route the Gulf is crossed by migrating birds at its widest point, from Louisiana southward. Still farther west, the numerous species of Plains and Rocky Mountains birds choose Mexico and Central America for the winter, and make a land journey of short stages that extends over several weeks.

As already stated, the longest migration route is taken by some of the wading birds, especially the American golden plover, the Eskimo curlew, and the turn-