Common Name

Scientific Name

Photo by Jim Weis
Photo Courtesy of Utah Division of Wildlife Resources

The tree swallow, Tachycineta bicolor, breeds near water in open woodlands in most of Canada, in Alaska, and in the northern United States. Small localized populations also breed in New Mexico and Arizona. The species winters in Florida, areas near the Gulf of Mexico, Baja California, and central Mexico. It is a common summer resident in the coniferous forests of northern and central Utah. During spring and fall migrations, large mixed flocks of swallows are seen in lowland areas of the state.

The diet of the tree swallow consists primarily of flying insects, which are captured and consumed during flight. Pairs participate in a complex courtship flight, and usually a monogamous pair bond is formed; when food is abundant, however, the male and female may mate with other individuals. Males select a tree cavity or nesting box before females arrive on the breeding grounds. Females then select a nest site occupied by a male. Competition for nesting sites is fierce, and both sexes vigorously defend the area. The female constructs a nest of grass within the tree cavity and then incubates her clutch of four to six eggs for about two weeks. The young are born naked and blind, and the female must stay with hatchlings for the first three days in order to keep them warm. The young leave the nest at about three weeks, and both parents continue to feed the young for three days afterwards.


  • Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The birderís handbook[:] a field guide to the natural history of North American birds. Simon & Schuster, New York. xxx + 785 pp.

  • Behle, W. H., Sorensen, E. D. and C. M. White. 1985. Utah birds: a revised checklist. Utah Museum of Natural History, Occasional Publication No. 4. Salt Lake City, UT.

  • Robertson, R. J., B. J. Stutchbury, and R. R. Cohen. 1992. Tree Swallow. Birds of North America 11.