Tree Swallows: Desirable Guest

Description, Range, Habitat, Nesting Habits, Food for Tree Swallows

May 10, 2007
Melissa Howard

male tree swallow - Melissa Howard

If you put up a bluebird house, do not be disappointed if a pair of tree swallows move in. They are delightful guests; beautiful, helpful, and entertaining.

Description

Tree swallows are beautiful birds about 5” long (which is roughly sparrow sized). The male is a dark-iridescent blue with a creamy breast. The female is dull gray above and a pale gray below. The male tree swallow has a neat appearance with a clever little face. Their song is a liquid warble.

Their flight is a flapping-gliding combination. Tree swallows fly “in circles, alternately losing altitude and then regaining it with three or four vigorous flaps.” (Simonds, 28)

Range:

Their breeding range includes the northern United States and extends far into Canada and up into Alaska.

They winter in coastal areas. Tree swallows’ winter range runs from Virginia south along the Gulf States to central California and extends south to Mexico and Central America.

Preferred Habitat

Open wooded swamps, woodlands, lakeshores, flooded meadows, marshes, and streams.

Courting Habits, Nesting Habits and Fledglings

Tree swallows court by indulging in a fluttery flight with much bowing and billing.

They build nests in tree cavities or nesting boxes that are five to ten feet off the ground. They require a 1.5-inch entrance hole. It takes 2-4 weeks to build the nest of dried grass lined with feathers. The male and female work together on the construction of the nest. Once the nest is built, the female lays 4-6 white eggs, which she incubates for 13-16 days (tree swallows raise one brood per year). Tree swallows may nest in groups or alone but whatever their social preference, they are defensive of their territory and defend it vigorously.

The parents cooperate in the feeding of the nestlings and in the cleaning of the nest. To feed the nestlings, tree swallow parents force insects down the youngsters’ throats until they can leave the nest and catch insects in flight. Tree swallow parents’prefer to drop the fecal sacs in water whenever possible. The baby birds remain in the nest for 16-27 days.

Unlike most fledglings, swallows are skillful flyers as soon as they leave the nest. They have to fly because their survival depends on catching flying insects.

Food

The tree swallow’s preference for insects should make him a welcome guest in your yard. A single nest of swallows eats up to a thousand insects a day. Think of the swallow as beautiful mosquito catcher. Tree swallows also enjoy berries and seeds.