Swallows
Hirundo rustica
The Barn Swallow is a graceful and familiar bird, recognized by its sleek, iridescent blue-black upperparts and deeply forked tail. This agile flyer is often seen darting over open fields and water, capturing insects mid-flight. Closely associated with human settlements, it frequently nests in man-made structures across its vast Northern Hemisphere breeding range.
Typical adult measurements.
Individuals and populations vary.
01 / The telltale details
Start with shape and behavior. Then look for the smaller details.
Glistening steel-blue back, wings, and deeply forked tail. Rufous to tawny underparts with a rusty forehead and throat, separated from the paler belly by a dark blue breast band.
Long, deeply forked tail with white spots visible on the outer end of the upper tail, especially in flight. Males typically have longer outer tail streamers than females.
Similar to males but generally less vibrantly colored, with a less glossy blue on the upperparts and breast band, and shorter outer tail streamers.
Browner overall with a paler rufous face and whiter underparts, lacking the elongated tail streamers of adults.
02 / A place in the world
Barn Swallows favor open country with low vegetation, such as agricultural areas, pastures, meadows, and farmland, often near water sources. They avoid heavily wooded or densely built-up regions. They commonly nest in human-made structures like barns, stables, under bridges, or on wharves.
This species has a vast global distribution, breeding across the Northern Hemisphere, including North America, Europe, northcentral Asia, northern Africa, the Middle East, southern China, and Japan. They migrate to winter in much of the Southern Hemisphere, including South America, sub-Saharan Africa, South Asia, Indonesia, and Micronesia.
Barn Swallows are long-distance migratory birds. Populations breeding in North America typically winter in Central and South America, while Eurasian populations generally winter in Africa, Arabia, and the Indian subcontinent. They migrate during the day, often feeding as they travel.
03 / Listen a little closer
Their vocalizations include a constant liquid twittering and chattering song, used for territory defense and mate attraction. They also have various calls, such as a "witt or witt-witt," a loud "splee-plink" when excited, and sharp alarm calls for predators.
04 / The life behind the feathers
Their diet consists almost entirely of insects, primarily flying insects such as flies (including house flies and horse flies), beetles, wasps, wild bees, winged ants, moths, damselflies, grasshoppers, and crickets. They also occasionally consume a few spiders and snails.
Barn Swallows are aerial insectivores, catching their prey in flight with remarkable agility. They often forage low over water or fields, sometimes following animals or farm machinery to capture disturbed insects. They also drink by skimming the surface of water bodies while flying.
Nests are cup-shaped, constructed by both sexes from mud pellets mixed with saliva, and lined with soft materials like grasses and feathers. They are typically built on sheltered ledges or beams inside barns, stables, under bridges, or other human-made structures. They may reuse nests from previous years.
Barn Swallows are socially monogamous, though extra-pair copulations are common. They often form breeding pairs each spring and may nest colonially. They are territorial around their nests and communicate using various vocalizations and body language.
One more reason to pay attention
The Barn Swallow is the most widespread swallow species globally, occurring on all continents except Australia and Antarctica.
Males may use deceptive alarm calls to disrupt extra-pair copulation attempts toward their mates.
Juveniles from an earlier brood may assist their parents in feeding a second brood.
05 / An eye for the difference
Barn Swallows have a deeply forked tail and a rusty throat, while Cliff Swallows have a squared tail and a pale rump.
Tree Swallows have pure white underparts and a less deeply forked tail compared to the Barn Swallow's tawny underparts and long, deeply forked tail.
The Barn Swallow can be distinguished from the Welcome Swallow by its deeply forked tail and white spots on the tail.
AI-assisted species research. Prepared September 2026. Details can vary across regions and populations.