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Barn Swallow (Hirundo rustica)

prepared by Paul Nicholson, London Bird Team, February 2022

A Barn Swallow’s deeply forked tail is one of the most useful field marks in identifying this beautiful species. Photos 1 and 2 by Paul Nicholson, Photos 3 and 4 by Brock and Sherri Fenton.

The Barn Swallow is a sleek, acrobatic flier. It is a delight to watch these petite birds dart over a pond or river, hunting for aerial insects. This species is one of six members of the swallow family that can be seen in London and Middlesex County. The Barn Swallow is listed as a Species at Risk of extinction in Ontario.


Adult Barn Swallows have shiny, very dark blue wings, back, tail, and cap with a rust-coloured forehead and throat and an orange underside. While the birds are in flight, you might also notice a white band on the tail.


Apart from the Barn Swallow’s impressive flying style, one of the best identification field marks is the bird’s deeply forked tail. Male Barn Swallows with longer tail streamers have been shown to live longer, fight disease more readily, and attract mates more successfully.


Barn Swallows can be seen in southern Ontario from April to September. They are long-distance migrants and spend each winter in Central and South America. Of more than 80 swallow species in the world, the Barn Swallow is one of the most widely distributed. It can be seen on all continents except for Antarctica. Partly because of this bird’s distribution and willingness to nest near humans, it has frequently been referenced in literature, myths, and popular culture. Many sailors have chosen a swallow tattoo because it symbolizes a safe return to land.


A common vocalization of the Barn Swallow is a twittery song.

Each spring, male and female Barn Swallow pairs will together build a nest of mud and grass, typically on some human-made structure. Before North America was colonized by Europeans, the Barn Swallow and some other aerial insectivore species like the Chimney Swift depended primarily on hollow mature or dead trees for providing structures on which they built their nests. However, the birds became known by the name Barn Swallow for what became one of their preferred nesting locations after colonization: wooden rural barns. Today, although the number of these barns is decreasing, this species has partly adapted. They now build nests now under a building’s eaves, in sheds, under bridges, or in dedicated little roofed structures on wooden stilts that you might see along some highways. In London, such structures can be found in the north part of Stoney Creek and just west of Meadowlily Woods. 

Learn more about the Barn Swallow’s life history.

This species was assigned “threatened” status nationally in 2017 by Canada’s Committee on the Status of Endangered Wildlife in Canada in accordance with the Species at Risk Act. The Barn Swallow is also on our Province’s Species at Risk in Ontario (SARO) list and is characterized as “threatened” because it is likely to become endangered if steps are not taken to address factors threatening it.


This species has struggled in the recent decades with food supply. As an aerial insectivore, Barn Swallows need to feed on flying insects such as flies, moths, and bees. The SARO website notes the ongoing replacement of old wooden barns and other structures in rural areas with metal constructions, but also points to “massive pesticide spraying of fields that can also reduce the insect population Barns Swallows need for food.” In addition to some agricultural practices, it is thought that climate change and in particular higher mean temperatures will further reduce the availability of insects.

The Province of Ontario’s recovery strategy for the Barn Swallow concedes that there are knowledge gaps in understanding the implications of threats these birds face: “It is likely that multiple direct and indirect threats at various stages and locations in its life cycle along with population fluctuations due to natural processes, are having an additive or synergistic impact on Barn Swallow populations.”


From spring to early fall, you might have success viewing Barn Swallows either at the forks of the Thames River in downtown London or while standing on the viewing platform behind the City of London welcome centre on Wellington Rd. S. Barn Swallows are widely dispersed throughout London and the surrounding area and can generally be seen in fields with natural vegetation, especially near the Thames River or other bodies of water. Information about local sightings of this bird can be found by clicking the “Explore” tab of the eBird Canada platform (click here) or on iNaturalist (click here).

Help make London friendlier for Barn Swallows:

  • Support efforts to mitigate and adapt to climate change.

  • Support the protection of natural habitats, which produce insects for birds to eat.

  • Grow native plants in your yard to help the life cycles of insects that, as adults, may become food for swallows. Learn more about landscaping for birds

  • Avoid use of pesticides and reduce your ecological footprint as much as possible.

  • If Barn Swallows nest on buildings that you manage, avoid disturbing their nests during spring and summer. Consider adding platforms to existing buildings to accommodate nests, or build a dedicated structure for barn swallows on your property – see here for more information. The Province of Ontario provides guidelines for creating habitat for nesting Barn Swallows.

  • Submit sighting records using the eBird or iNaturalist citizen science platforms. 

  • Monitor buildings for Barn Swallow nests during spring and summer. If Barn Swallow nesting activity is observed at or near an active construction site, please contact the Ontario Natural Heritage Information Centre

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