peculiarly liable to destruction by striking high objects. A new tower in a city kills many before the survivors learn to avoid it. The Washington monument has caused the death of many little migrants; and though the number of its victims has decreased of late years, yet on a single morning in the spring of 1902 nearly 150 lifeless bodies were strewn around its base.
Bright lights attract birds from great distances. While the torch in the Bartholdi Statue of Liberty in New York Harbor was kept lighted, the sacrifice of life it caused was enormous, even reaching a maximum of 700 birds in a month. A flashing light frightens birds away and a red light is avoided by them as if it were a danger signal, but a steady white light looming out of the mist or darkness seems to act like a magnet and draws the wanderers to destruction. Coming from any direction, they veer around to the leeward side, and then, flying against the wind, dash themselves against the pitiless glass.
DISTANCE OF MIGRATION.
The length of the migration journey varies enormously. Some birds do not migrate at all. Many a cardinal, Carolina wren, and bobwhite rounds out its whole contented life within ten miles of its birthplace. Other birds, for instance, the pine warbler and the blackheaded grosbeak, do not venture in winter south of the breeding range, so that with them the fall migration is only a withdrawal from the northern and a concentration in the southern part of the summer home—the the warbler in about a fourth and the grosbeak in less than an eighth of the summer area.
The next variation is illustrated by the robin, which occurs as a species in the middle districts of the United States throughout the year, in Canada only in summer, and along the Gulf of Mexico only in winter. Probably no individual robin is a continuous resident in any section; but the robin that nests, let us say, in southern Missouri, will spend the winter near the Gulf, while his hardy Canada-bred cousin will be the winter tenant of the abandoned summer home of the southern bird.
Most migrants entirely change their abode twice a year, and some of them travel immense distances. Of the land birds, the common eastern nighthawk seems to deserve first place among those whose winter homes are widely distant from the breeding grounds. Alaska and Patagonia, separated by 115 degrees of latitude, are the extremes of the summer and winter homes of the bird; and each spring many a nighthawk travels the 5,000 miles that lie between. But some of the shore birds are still more inveterate voyagers. These cover from 6,000 to 8,000 miles each way, and appear to make traveling their chief occupation.
ROUTES OF MIGRATION.
Birds often seem eccentric in choice of route, and many land birds do not take the shortest line. The fifty species from New England that winter in South America, instead of making the direct trip over the Atlantic, involving a flight of 2,000 miles, take a slightly longer route which follows the coast to Florida, and passes thence by island or mainland to South America. What would seem at first sight to be a natural and convenient migratory highway extends from Florida through the Bahamas or Cuba to Haiti, Porto Rico, and the Lesser Antilles, and thence to South America. The bird that travels by this route need never be out of sight of land; resting places may be had at convenient intervals, and the distance is but little longer than the water route. Yet, beyond Cuba, this highway is little used. About twenty-five species continue as far as Porto Rico and re-
