This iridescent little flier darts through the sky scooping insects out of midair at up to 25 miles per hour (40 kph). Tree swallows are most commonly found near water and in open areas with some sheltering trees and shrubs.
Tree swallows are very social and are usually found in flocks. During migration, their flocks may number in the hundreds of thousands. The birds nest in cavities, but do not create the cavities themselves. They gladly move into nest boxes or communal “bird condos” such as those erected for purple martins, and are also very fond of hollow, dried gourds hung out for nesting.
Tree swallows use feathers from many other birds in their nests, which keeps their nestlings warm and may ward off mites and other insect pests. Research also shows that nests with more feathers result in young that leave the nest earlier. Adult swallows put on dazzling acrobatic displays as they fight each other over suitable feathers found floating on the breeze. Amusingly, the victorious parent will often take to the air again and drop the feather, as if simply for the thrill of the chase.
Photo: John Benson