Tachycineta bicolor
Order Passeriformes
Family Hirundinidae
Other names: White-bellied Swallow
♂ Adult male.— Upper parts greenish-blue, especially bright in strong light; under parts pure white; tail notched, but not deeply.
♀Adult female.— Upper parts usually duller.
Immature.— Upper parts brown; a faint incomplete dusky collar across the breast.
Nest, in a hole in a tree, or in a box. Eggs, white.
The White-bellied Swallow is a summer resident throughout New England and the Hudson Valley, but it is only locally common. Many of the boxes formerly tenanted by Swallows are now occupied by English Sparrows. In pure farming country, as along the Concord River, the White-bellied Swallow is still a characteristic feature of the farm. In wilder country, in northern New England, and occasionally throughout its range, it nests in deserted woodpecker holes in trees. About the first of April the earliest arrivals appear along the sea-shore, or some lake or river, and in a week or two their shrill notes are heard about the farmhouses where they breed. As early as July migrants begin to return from the north, and multitudes now collect over the marshes and along the beaches at the sea-shore, fringing the telegraph wires for rods, hovering in clouds over the bayberry bushes, the fruit of which they eat, or sunning themselves on the sand. A few stay into October.
The notes of the Tree Swallow are generally sharp and high, but occasionally sweet and twittering. Near a breeding-site the male may be heard singing before dawn, either from the box, or as he flies to and from in the darkness.
The pure white under parts distinguish this swallow from both the Barn and Eave Swallows [Cliff Swallow], each of which has a reddish-brown chin. The Bank or Sand Swallow has a brownish band across the upper breast. Young White-bellied Swallows not only lack the steel-blue of the adult, but have a faint brownish collar nearly across the breast; they must therefore be carefully distinguished from the Bank Swallow, which has a broad dark band completely across the breast. The flight of all four swallows may be distinguished after much practice. The White-bellied often hangs in the wind with outspread wings and tail, and back curved like a dolphin.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)