The tree swallow is 4.7-5.9 inches (12-15 cm) with a wingspan of 11.8-13.8 inches (30-35 cm)
It has a forked tail; a metallic green to blue head, back, and wing feathers; and white feathers on its breast and belly. It has a small black bill, dark brown eyes, and light brown legs and feet.
Females are duller in color than males, and their foreheads may be a brownish color.
Habitat
The tree swallow is found in wet habitats like flooded meadows, marshes, lakeshores, streams, and open areas near woods.
The male tree swallow arrives at the breeding territory a week before the female. Once the female arrives, breeding pairs form. Male and female pairs defend their nesting territory. A pair has more than one nesting site, usually in a tree cavity, but they will use only one site for their eggs.
The female builds a cup-shaped nest using grass or pine needles. Both the male and the female collect feathers to line the nest. The female tree swallow lays 4-6 eggs at a rate of one egg per day. The female incubates the eggs, and the male guards the nesting site.
The eggs hatch in about two weeks. Both the male and the female feed the chicks. The chicks fledge (develop flight feathers) in about three weeks.
The tree swallow has a lifespan of around 2.7 years.
Behavior
The tree swallow is a short-distance migrator. It gathers in large flocks in the fall. It is the first swallow to reappear in the spring.