- ORDER: Passeriformes
- FAMILY: Hirundinidae
Handsome aerialists with deep-blue iridescent backs and clean white fronts, Tree Swallows are a familiar sight in summer fields and wetlands across northern North America. They chase after flying insects with acrobatic twists and turns, their steely blue-green feathers flashing in the sunlight. Tree Swallows nest in tree cavities; they also readily take up residence in nest boxes. This habit has allowed scientists to study their breeding biology in detail, and makes them a great addition to many a homeowner’s yard or field.More ID Info
Find This Bird
Tree Swallows are easy to find in much of North America from spring through fall. Head to open fields or marshes adjacent to bodies of freshwater. Scan the air for flying birds, look along utility wires and shrubs for perched birds. Also check any nest boxes you happen to see; in summer Tree Swallows spend lots of time sitting on or flying around them. Tree Swallows are vocal; listen for their sweet, chirping calls as they wheel around overhead in pursuit of insects. In the winter you can find Tree Swallows in the extreme southeastern and southwestern United States as well as south of the border.
- Golondrina bicolor (Spanish)
- Hirondelle bicolore (French)
Tree Swallows may supplement their insect diet with berries, such as fruit from bayberry and myrica shrubs. During the breeding season, when they need extra calcium to produce eggs, the swallows may search through backyard compost piles for pieces of eggshells to eat.
If you live in their breeding range, there’s a good chance you can attract Tree Swallows to your yard by putting up a nest box. Make sure you put it up well before breeding season. Attach a guard to keep predators from raiding eggs and young. Find out more about nest boxes on our Attract Birds pages. You'll find plans for building a nest box of the appropriate size on our All About Birdhouses site.
- Cool Facts
- Migrating and wintering Tree Swallows can form enormous flocks numbering in the hundreds of thousands. They gather about an hour before sunset and form a dense cloud above a roost site (such as a cattail marsh or grove of small trees), swirling around like a living tornado. With each pass, more birds drop down until they are all settled on the roost.
- Tree Swallows winter farther north than any other American swallows and return to their nesting grounds long before other swallows come back. They can eat plant foods as well as their normal insect prey, which helps them survive the cold snaps and wintry weather of early spring.
- The Tree Swallow—which is most often seen in open, treeless areas—gets its name from its habit of nesting in tree cavities. They also take readily to nest boxes.
- Tree Swallows have helped researchers make major advances in several branches of ecology, and they are among the best-studied bird species in North America. Still, we know little about their lives during migration and winter.
- The oldest Tree Swallow on record was at least 12 years, 1 month old when it was recaptured and released during banding operations in Ontario in 1998.