Guide to North American Birds

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Photo: Claude Nadeau/Vireo

Cliff Swallow

Petrochelidon pyrrhonota

This swallow is probably far more common today than when the Pilgrims landed. Originally it built its jug-shaped mud nests on the sides of cliffs. However, the sides of barns and the supports of bridges provided sheltered sites that were far more widespread than the natural ones. Taking advantage of these artificial locations, the species has invaded many areas where it never nested before. Although it is continuing to spread in the east, it is still more common in the west, where practically every culvert and highway bridge seems to have its own Cliff Swallow colony.

Conservation status	Declines have been noted in a few areas, but general continent-wide trend is toward wider range and higher numbers.
Family	Swallows
Habitat	Open to semi-open land, farms, cliffs, river bluffs, lakes. Widespread in all kinds of semi-open country, especially near water, from prairies to desert rivers to clearings in northern forest. Breeds where it can find sheltered vertical cliffs or other surfaces for nesting and a supply of mud for building the nest; still unaccountably scarce or missing in some seemingly suitable areas.

Photo Gallery

Feeding Behavior

Feeds mostly on the wing. Often forages in flocks, and may feed low over the water or very high over other terrain. In bad weather, may feed on ground.

Eggs

4-5, sometimes 3-6. White to pale pinkish, spotted with brown. Incubation is by both parents, 14-16 days. Young: Both parents bring food for nestlings. Young leave nest about 21-23 days after hatching.

Young

Both parents bring food for nestlings. Young leave nest about 21-23 days after hatching.

Diet

Insects. Feeds mostly on a wide variety of flying insects, particularly beetles (including june beetles and adult weevils), true bugs, flies, winged ants, bees, and wasps. Also eats grasshoppers, mayflies, lacewings, and various other insects, plus some spiders. Occasionally eats berries.

Nesting

Typically nests in colonies, sometimes with hundreds of nests crowded close together. Nest site is usually on vertical surface with some overhead shelter. Natural sites were on cliffs; most sites today on sides of buildings, under bridges, in culverts, or similar places. Nest is made of dried mud and shaped like a gourd, with large chamber for nest, narrowing to small entrance on side. Both sexes help build nest; inside of nest sparsely lined with grass and feathers. May repair and reuse old nest, sometimes that of another species.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

A long-distance migrant, wintering in southern South America. Migrates in flocks, traveling by day. This is the famous swallow that returns to the mission in San Juan Capistrano, California, every spring; traditionally the return is celebrated on March 19th, although the birds actually return to the general area in late February.