- 5.9–7.5 in
- 11.4–12.6 in
- 0.6–0.7 oz
- Slightly smaller than a bluebird; slightly larger than a Tree Swallow
- Hirondelle des granges, Hirondelle rustique, Hirondelle de cheminée (French)
- Golondrina ranchera, Golondrina tijerela (Spanish)
- The Barn Swallow is the most abundant and widely distributed swallow species in the world. It breeds throughout the Northern Hemisphere and winters in much of the Southern Hemisphere.
- Barn Swallows once nested in caves throughout North America, but now build their nests almost exclusively on human-made structures. Today the only North American Barn Swallow population that still regularly uses caves as nest sites occurs in the Channel Islands off the California coast.
- Barn Swallow parents sometimes get help from other birds to feed their young. These “helpers at the nest” are usually older siblings from previous clutches, but unrelated juveniles may help as well.
- An unmated male Barn Swallow may kill the nestlings of a nesting pair. His actions often succeed in breaking up the pair and afford him the opportunity to mate with the female.
- Although the killing of egrets is often cited for inspiring the U.S. conservation movement, it was the millinery (hat-making) trade’s impact on Barn Swallows that prompted naturalist George Bird Grinnell’s 1886 Forest & Stream editorial decrying the waste of bird life. His essay led to the founding of the first Audubon Society.
- According to legend, the Barn Swallow got its forked tail because it stole fire from the gods to bring to people. An angry deity hurled a firebrand at the swallow, singeing away its middle tail feathers.
- The oldest known Barn Swallow in North America was 8 years, 1 month old.
Barn Swallows forage in open areas throughout most of the continent, including suburban parks and ball fields, agricultural fields, beaches, and over open water such as lakes, ponds and coastal waters. They range from sea level up to 10,000 feet. Breeding habitat must include open areas for foraging, structures or cliffs to build nests on, and a source of mud such as a riverbank to provide the material for building nests.
Flies of all types make up the majority of the Barn Swallow’s diet, along with beetles, bees, wasps, ants, butterflies, moths, and other flying insects. Barn Swallows usually take relatively large, single insects rather than feeding on swarms of smaller prey. They will also pick up grit and small pebbles, or eggshells and oyster shells set out by humans, which may help the birds digest insects or add needed calcium to the diet.
- Clutch Size
- 3–7 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 0.6–0.8 in
- Egg Width
- 0.5–0.6 in
- Incubation Period
- 12–17 days
- Nestling Period
- 15–27 days
- Egg Description
- Creamy or pinkish white, spotted with brown, lavender, and gray.
- Condition at Hatching
- Eyes closed, naked except for sparse tufts of pale gray down.
Both male and female build the nest cup using mud. They collect mud in their bills and often mix it with grass stems to make pellets. They first construct a small shelf to sit on, then build up the nest’s sides. If built against a wall or other vertical surface the result is a semicircular, half-cup shape. Nests built on top of a beam or other horizontal surface form a complete cup about 3 inches across at the rim and 2 inches deep. The birds line the cup first with grass, then feathers, and in colonies may steal nest-lining materials from neighboring nests. When reusing nests, Barn Swallows clean out old feathers and add new mud to the nest’s rim.
Barn Swallow pairs explore a number of potential nesting spots, flying up and hovering to investigate a location, then moving to another site before narrowing their choice. Preferred sites include eaves, rafters, and cross beams of barns, sheds and stables, as well as the undersides of bridges, wharfs, and culverts. They may also use nests from previous years, but avoid those infested heavily with mites or other parasites.
© 2004 Cornell Lab of Ornithology
Watch for the Barn Swallow’s smooth, fluid wingbeats and the way they pull their wingtips back at the end of each stroke. These birds feed almost exclusively in flight, flying lower than many other swallow species and often nearly hugging the ground or water surface. They catch flies and other prey in midair above fields, marshes, lakes, and coastal waters, and often follow farm implements, cattle herds, and humans to snag flushed insects. They occasionally feed on sluggish or dead insects on the ground, and in cold weather will pluck flies off barn walls. Barn Swallows also drink and even bathe on the wing, dipping down to take a mouthful of water or touch their belly to the surface for a quick rinse. Males defend a small territory around the nest site and aggressively chase away other males, even grabbing them with their feet and tumbling to the ground. Individuals or groups of Barn Swallows mob predators such as hawks, gulls, or grackles that approach nests.
The North American Breeding Bird Survey estimates that Barn Swallow populations have declined throughout their range between 1966 and 2010, most notably in Canada where there has been a 3.8 percent decline per year (amounting to a cumulative decline of 82 percent). Partners in Flight estimates a global breeding population of 120 million, with 24 percent breeding in the U.S., 4 percent in Canada, and 2 percent in Mexico. They rate an 8 out of 20 on the Continental Concern Score and are not on the 2012 Watch List. Barn Swallows were hunted for the hat trade in the nineteenth century, and are still hunted for food in parts of their wintering range. Discarded twine or fishing line can pose a problem when Barn Swallows use these materials to line their nests, where the strands can entangle adults or young and trap them. On a more positive note, this species has benefited from human-made structures, and people generally encourage these pretty, insect-eating birds to nest near them. As a result, Barn Swallows have greatly expanded their breeding range and numbers as people have settled the continent.
- Brown, C. R., and M. B. Brown. 1999. Barn Swallow (Hirundo rustica). In The Birds of North America, No. 452 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
- Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The Birder’s Handbook. Simon & Schuster Inc., New York.
- Myers, G. R. and D. W. Waller. 1977. Helpers at the nest in Barn Swallows. Auk, 94;3, 596.
- Partners in Flight. 2012. Species assessment database.
- Peterson, R.T. 2008. Field Guide to Birds of North America. Houghton Mifflin Co.
- Sibley, D. A. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York
- USGS Patuxent Wildlife Research Center. 2012. North American Breeding Bird Survey 1966–2010 analysis.
Long-distance migrant. Barn Swallows fly from North American breeding grounds to wintering areas in Central and South America. Southbound fall migration may begin by late June in Florida or early July in Massachusetts. They return as early as late January in southern California to mid-May at Alaskan breeding sites.
Barn Swallows don't come to seed or suet feeders, but they may take ground-up eggshells or oyster shells placed on an open platform feeder. If you have a suitable outbuilding, leaving a door or window open can encourage Barn Swallows to build a nest inside. Providing a source of mud will also help with nest building. Barn Swallows may use artificial nest cups attached to an appropriate surface.
Find This Bird
Look for Barn Swallows feeding above meadows, fields, and farmyards and over water, or perched on wires near feeding areas and nesting sites. During the breeding season keep an eye on mud puddles, as Barn Swallows come to the ground to pick up mud and grass for nesting materials. Their mud nests are often tucked under the eaves of barns and stables, on structures near playing fields, or under bridges. You can find Barn Swallows across most of North America.
Barn Swallow is one of the focal species in our Celebrate Urban Birds citizen-science project.