Photo: Bob Feldman/Audubon Photography Awards

Tree Swallow

Tachycineta bicolor

The popularity of the bluebird has been a boon to the Tree Swallow, which nests in holes of exactly the same size, and has taken advantage of bluebird houses over much of North America. In regions with no such ready supply of artificial nest sites, the swallows must compete with other cavity-nesting birds, arriving early in spring to stake out territories. Unlike other swallows, Tree Swallows eat many berries (especially bayberries), allowing them to survive through wintry spells when other insect-eaters might starve.
Conservation status Widespread and common, and population apparently increasing in many areas.
Family Swallows
Habitat Open country near water, marshes, meadows, lakes. May breed in any kind of open or semi-open area that provides both nesting sites and a good supply of flying insects. Typically breeds close to water, as around ponds or marshes, but also nests away from water around meadows or brushy areas. In winter, mainly around marshes and near bayberry thickets along coast.
The popularity of the bluebird has been a boon to the Tree Swallow, which nests in holes of exactly the same size, and has taken advantage of bluebird houses over much of North America. In regions with no such ready supply of artificial nest sites, the swallows must compete with other cavity-nesting birds, arriving early in spring to stake out territories. Unlike other swallows, Tree Swallows eat many berries (especially bayberries), allowing them to survive through wintry spells when other insect-eaters might starve.
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Feeding Behavior

Forages mostly in flight, often low over water or fields. May pick items from surface of water while flying. Perches in bushes to eat berries, and sometimes feeds on ground, especially in cold weather.


Eggs

4-7, sometimes 2-8. Very pale pink at first, fading to white. Incubation is by female only, usually 14-15 days. Young: Both parents feed nestlings, and female broods them while they are small. Young usually leave the nest about 18-22 days after hatching.


Young

Both parents feed nestlings, and female broods them while they are small. Young usually leave the nest about 18-22 days after hatching.

Diet

Mostly insects, some berries. Diet is mostly insects, especially in summer. Feeds on many flies, beetles, winged ants, and others. Also eats some spiders, and will eat sand fleas (which are crustaceans). Unlike our other swallows, eats much vegetable material (up to 20% of annual diet, mostly eaten in winter). Bayberries are main plant food, also eats other berries and seeds.


Nesting

Male arrives on nesting territory before female; courtship involves male showing female potential nesting sites. Birds often choose new mates each year. Nest: Natural nest sites are in holes in dead trees, or in old sapsucker holes in live trees; also very frequently uses nest boxes. Sometimes in odd sites such as holes in buildings, old Cliff Swallow nests, or holes in ground. Nest (built mostly by female) is cup of grass, weeds, rootlets, moss, pine needles, other plant materials. Usually lined with many feathers (from other kinds of birds), mostly added after first eggs are laid.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Migrates north relatively early in spring. Southward migration begins as early as July, peaks in early fall. Migrates by day, in flocks.

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Migration

Migrates north relatively early in spring. Southward migration begins as early as July, peaks in early fall. Migrates by day, in flocks.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Cheerful series of liquid twitters.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How Climate Change Will Reshape the Range of the Tree Swallow

Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.

Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.

Climate threats facing the Tree Swallow

Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.

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