Length: About 6 inches.

General Appearance: Bluish-green above; pure white underneath, from beak to tail; tail not deeply forked; wings very long.

Male and Female: Back, a dark, glistening green, giving this swallow the name of “The Green-backed Swallow”; the snowy white under parts give it the names of “White-breasted Swallow” and “White-bellied Swallow.” The green and white are about equally distributed; the green on the head resembles a close-fitting skull-cap, pulled down below the eyes. Wings, very long and powerful (nearly 4¾ inches), extending beyond the ends of the forked tail. Bill short, very wide at base. Feet small and weak—used only when resting, as swallows are generally on the wing.

Young: Brownish-gray, white beneath.

Note: A pleasant twitter.

Flight: Swift, in great circles.

Habitat: Tree swallows are seen along roadsides, and near swamps and thickets. They formerly nested in dead trees, in woodpeckers’ holes, or any available hollow. They now take kindly to nesting-boxes. They have “roosts” at night where they resort in great numbers, especially on their way south in the late summer. They have a great fondness for telegraph-wires. During the fall migration, long chains of these swallows are festooned on the wires during the daytime. At night they disappear to their roosts, preferably near marshes. They are a sight to be remembered in the Jersey marshes, which Mr. Horsfall’s accompanying drawing depicts.

Range: North America from Alaska and northern Canada to southern California, Colorado, Kansas, Missouri, and Virginia. They winter from central California, southern Texas, southern parts of the Gulf States and southeastern North Carolina, south over Mexico, Guatemala, and Cuba; sometimes in New Jersey. They eat bayberries that grow along the coast, and thus are able to remain farther north in winter than their relatives.

First of the swallow host to speed northward is the Tree Swallow, that migrates in April, as soon as a sufficient number of insects have hatched to furnish a living for these almost wholly insectivorous birds. Their cheerful twitter and beautiful circling flight make them very welcome.

Swallows have always been regarded with favor. They were formerly considered a good omen, and were thought to bring fair weather and prosperity. I shall always remember the welcoming swallow that met our ship near the Scilly Islands one June day, and preceded us without resting for long hours as we voyaged close to the shore of England. It seemed to presage the good fortune that followed us.

Swallows fly with their broad beaks ready to open, and catch unwary insects with great ease. They rise early and continue their ceaseless quest for small beetles, flies, mosquitoes, and other insects. Professor Beal says: “Most of these are either injurious or annoying, and the numbers destroyed by swallows are not only beyond calculation but almost beyond imagination.”[92] He pleads for the protection of all swallows and suggests that the “white-bellied swallows” be supplied with boxes similar to those constructed for bluebirds, only placed at a greater elevation and protected from cats.

Tree swallows are the first to come and first to go. Before the summer has really arrived, as early as July first, they begin to flock and form great colonies that may be seen migrating during the daytime.