The Tree Swallow (Tachycineta bicolor) is a small, migratory bird found across North America. Measuring about 5-6 inches in length and weighing between 0.6-0.8 ounces, the Tree Swallow is one of the smallest swallow species in North America. Its wingspan ranges between 11-13 inches.
The Tree Swallow has distinguishing field marks that make it easy to identify. The male and female have similar appearances, with metallic blue-green feathers on the back and head, white underparts, and a forked tail. The bird’s wings are long and pointed, which aids in its aerial acrobatics. The Tree Swallow’s white belly distinguishes it from other blue-green swallow species, like the Violet-green Swallow, which has a greenish belly.
During the breeding season, the Tree Swallow can be found nesting in tree cavities or man-made nest boxes. They are aerial insectivores, feeding on insects they catch while in flight. In the winter, Tree Swallows migrate south to warmer climates in Central and South America. Some populations, particularly in western North America, may be non-migratory, staying in their breeding grounds year-round.
Tree Swallows are known for their synchronized flying patterns, particularly during migration when they fly in large flocks. The birds often fly in a tight formation, with individuals darting in and out of the group, creating an impressive display of aerial coordination.
While the Tree Swallow is not considered a threatened species, habitat loss and degradation can negatively impact their populations. Providing nest boxes in suitable habitats can help support these birds during the breeding season, particularly in areas where natural tree cavities are scarce.