Swallows: Hirundinidae

Physical characteristics: The barn swallow has iridescent dark blue plumage on its back, with a dark orange throat and orange to buff breast, although there are some coloring variations among the six subspecies of the bird. It is the only species of swallow that has a long, deeply forked tail. The average size of the barn swallow is 7.5 in (19 cm) long with a weight of .6 oz (17 g).

Geographic range: During the summer months, barn swallows can be found throughout North America. The birds have the most widespread range of any swallow species, and are also found throughout Europe, Asia, Myanmar, Israel, and northern Africa. North American barn swallows winter in Central and South America, while their European and Asian counterparts migrate to central and southern Africa and south and Southeast Asia.

Habitat: During breeding season, barn swallows settle in habitats with abundant insects and some access to wet earth (such as from riverbanks or drainage ditches). They build their cone-shaped, open-topped mud nests in sheltered natural areas, including cliff overhangs and caves. They also quite frequently choose human-made structures to house their families, creating nests in the rafters of barns, the underside of highway overpasses, and the eaves of other buildings.

Barn swallow nests hold three to six eggs, and both female and male may share incubation and feeding duties. (Dwight Kuhn/Bruce Coleman Inc. Reproduced by permission.)

Because of their abundant insect population, farms make ideal places for barn swallows to live, and the birds can frequently be seen flying close to crops feeding on insects. Along with feathers, the straw and mud that are found in livestock areas also make excellent building materials for a barn-based nest. Barn swallows migrate towards warmer climates in the winter, and can be found in drier climates, such as the desert, when nesting isn't a priority.

Diet: Barn swallows feed on flying insects.

Behavior and reproduction: Barn swallows return to the same area each year to breed, hatch, and fledge, raise until they can fly, their young. Often, they will use the same nest year after year if it remains intact. Building a mud nest may take anywhere from a week to a month, and both male and female work together, using thousands of mud pellets carried one by one in their bills. Straw and grass are also used, and the nests are lined with feathers. Barn swallow nests hold three to six eggs, and both female and male may share incubation duties, sitting on the eggs to keep warm. The birds are colonial, meaning that they often build nests in groups; however, males will defend their nest vigorously from both predators, animals that hunt them for food, and other barn swallows.

Barn swallows and people: Because of their appetite for flying insects that annoy, destroy vegetation, and can carry disease, barn swallows are popular neighbors, particularly to farmers.

Conservation status: Barn swallows are abundant, and not considered threatened. ∎

American cliff swallows build their mud nests not only on the underside of cliffs, but also on the outside of overhanging human-made structures, such as bridges and dams. (© Brenda Tharp/Photo Researchers, Inc. Reproduced by permission.)