Barn swallow (Hirundo rustica)
|French:||Hirondelle de cheminée|
|Size||Length: 18 cm (2)|
|Weight||16 - 24 g (2)|
Classified as Least Concern (LC) on the IUCN Red List (1).
Not only does the barn swallow have the distinction of being the most widely distributed and abundant of all swallows, it is also one of the most familiar bird species in the world (3) (4). Having historically bred in caves, today it has almost completely converted to constructing its nest under the eaves of buildings, and it is this long association with human habitation that makes it quite so familiar, as well as earning the species its common name (3). This popular bird is admired for its supreme agility in flight, with a slender body, long, narrow, pointed wings, and a deeply-forked tail with long streamers allowing the barn swallow to spend most of its time on the wing (5). It has an attractive plumage of steely blue-black upperparts, red throat, and black wings and tail that sit in start contrast to pale underparts (2) (6). The male and female bird are very similar in appearance, although the tail streamers tend to be longer on the male, but the juvenile has paler underparts and a less deeply forked tail (3).
The barn swallow breeds across most of North America, Europe and Asia, and before the onset of winter, this long-distance migrant travels southwards to spend the winter in tropical Africa, Central and South America, South Asia and Southeast Asia, Australia or Micronesia (3) (7).
Historically, the barn swallow inhabited mountainous areas and coastlines with caves that provided areas for nesting. Today, however, due to human-built artificial structures providing additional nesting areas, the barn swallow is found in a greater variety of habitats (3). It prefers to forage over open country and cultivated areas near water, up to an altitude of 3,000 metres. In Europe and North America it is usually found in these rural areas, as it prefers to breed in farm buildings, but in Africa and Asia it is more common in busy towns and cities. Outside of the breeding season, the barn swallow gathers near wetlands where it roosts in dense vegetation near water (2).
An impressively agile flier, the barn swallow is capable of sharp turns and twists while pursing its flying insect prey. Typically, it hunts alone during the day over open areas, usually between one and ten metres above the ground, although insects are also plucked off the walls of artificial structures during periods of bad weather (3). It may also follow other animals and vehicles to take insects flushed by such disturbance (2). The barn swallow spends the majority of its time in the air, only descending to the ground to collect mud, grass or feathers to build its nest while breeding (3).
The barn swallow usually breeds between May and August depending upon the location. At the start of the breeding season, the male bird attracts a female mate by displaying its spread tail and by singing while circling high above the nest site (2) (3). Usually new pairs form each season, but partners may mate in successive seasons if they are successful in raising a brood the first time round (2). Both birds cooperate to build a cup-shaped nest, and the male bird defends a territory around this simple structure from other swallows by attacking intruders, chasing them and pecking at their feathers (3). Usually three to six eggs are laid and incubated, mostly by the female, for around 13 to 16 days. The chicks are brooded and fed by both birds, and the chicks grow quickly to become fully independent at only two weeks of age (2).
For a bird of such small size, the barn swallow undertakes hugely impressive, long-distance migrations. Birds are generally at the northern breeding grounds between April and October, before collecting into huge post-breeding flocks that sometimes number several hundred thousand, occasionally millions, of birds. The autumn southward migration takes several months, with most European birds travelling to Africa, while Asian birds travel to South Asia, Southeast Asia and Australia, and North American birds travel to Central and South America, as far south as northern Argentina. The timing of arrival back at the breeding grounds is dependant upon the severity of the weather, but the older males generally arrive first, with the females and younger males soon following (2).
The barn swallow is an extremely abundant bird that in many places has greatly benefited from the human alteration of the landscape. The availability of nesting sites once limited the size of its population, but now that the species has almost completely converted to building its nests on artificial structures, it has become very common. This popular bird has also largely avoided persecution, although it was exploited for the hat-making trade in North America in the 1800s, and many people even choose to protect the species’ nests on their buildings (3). The barn swallow population does, however, fluctuate in size quite significantly, and although extreme weather patterns are most likely the cause of this, the intensification of agriculture across its range and a reduction of prey availability from pesticide use may have also caused some declines (2).
As the barn swallow is not currently considered to be threatened with extinction, it is not the target of any known specific conservation measures. In some areas, however, it has benefited from farmers nailing narrow ledges to walls or under the eaves of buildings to provide additional support for the swallow’s nests (3).
To find out more about the conservation of birds, see:
Royal Society for the Protection of Birds:
American Bird Conservancy:
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- Incubate: to keep eggs warm so that development is possible.
- Territory: an area occupied and defended by an animal, a pair of animals or a colony.
IUCN Red List (September, 2010)
- del Hoyo, J., Elliott, A. and Sargatal, J. (2004) Handbook of the Birds of the World. Volume. 9: Cotingas to Pipits and Wagtails. Lynx Edicions, Barcelona.
Brown, C.R. and Bomberger Brown, M. (1999) Barn swallow (Hirundo rustica). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca: Available at:
Schulenberg, T.S. (2010) Common moorhen (Gallinula chloropus). In: Neotropical Birds Online. Cornell Lab of Ornithology, Ithaca. Available at:
- Perrins, C. (2009) The Encyclopedia of Birds. Oxford University Press, Oxford.
Royal Society for the Protection of Birds (September, 2010)
BirdLife International (September, 2010)