Tree Swallows nest in hollow trees, especially near water, but they also find and occupy backyard birdhouses. They compete vigorously with bluebirds who like the same size and type of house. During spring and summer evenings, tree swallows swoop and swirl through the air above lawns and trees, catching insects in their open mouths. They use white feathers both to line nests and for play.
Look For: The male is metallic blue-green above, white below. Female is duller. Juveniles are gray-brown above. The tail is notched.
Length: 5-6".
Habitat: Fields, marshes, waterways.
Range: Summer: Alaska, Canada, and much of U.S. Winter: Atlantic and Gulf coasts, southern Pacific coast.