13-15 cm (5-6") Common across North America. Open areas near water and woods.
Dark, iridescent blue-green above, may be greener in fall. Clear white below. White of cheek does not extend above eye or higher up on rump as in Violet-green Swallow.
Immature: gray-brown above, white below with a grayish diffuse breast band; similar Bank Swallow has distinct breast band.
Nests in tree cavities and bird houses.
Song: cheerful series of liquid twitters.