Widespread in Nortern Hemisphere. Winters in Costa Rica to Argentina, Africa, southern Asia. Migrates in flocks, mostly by day. Southward migration is well underway by mid-August.
One of the most familiar birds in rural areas and semi-open country, this swallow skims low over fields in a graceful flight. It is highly adaptive to humans as neighbors, building nests in barns or garages, or under bridges and wharves. It is now rare to find a Barn Swallow next in a site that is not manmade.
Almost entirely insects, finding a wide variety of flying insects, including houseflies, horseflies, beetles, wasps, wild bees, winged ants and true bugs. Only occasionally eat a few berries or seeds. Food is mostly captured and eaten in the air. Forages in long continuous flight, pursuing insect and catching them in its bill.
Courtship invloves aerial chases. On perch, pair sits close together, touch bills, preen each other's feathers. Serveral pairs may nest in the same immediate area, but do not form dense colonies like some swalows.
Original sites were in sheltered crevices in cliffs or shallow caves. Sites today are mostly in open buildings, under eaves, under bridges or docks, or similar places. Nest is a cup of mud and grass, lined with feathers. Both sexes help build the nest in scooping up pellets of mud and plastering them in place.
4-5, sometimes 6, rarely 7. White, spotted with brown. Incubation is by both sexes (female does more), 13-17 days.
Both parents feed the young. One or two additional birds, the pair's offspring from previous broods, may attend the nest and sometimes feed the nestlings. Young leave the nest about 18-23 days after hatching. 1 or 2 broods per year.