|Species: Barn Swallow
The Barn Swallow is
the most widely distributed and abundant swallow in the world. It
breeds throughout most of North America, Europe, and Asia and
winters in Central and South America, southern Spain, Morocco,
Egypt, sub-Saharan Africa, the Middle East, India, Indochina,
Malaysia, and Australia.
Barn Swallow is the most widespread species of swallow in the world
and a familiar inhabitant of barns and other outbuildings. A bird of
open country it was originally a cave breeder but now normally uses
man-made structures to breed and consequently has spread with human
swallow 6.75 inches long (17–20 g), with long forked tail. Adults
(Definitive Basic plumage) have steely-blue upperparts, rufous
underparts, and chestnut forehead. Tail is deeply forked, with white
spots on inner webs. Length of outermost tail-streamers varies
between sexes and ages but is always much greater than in any other
North American swallow species.
Adult Male: Sexes are similar, but males have longer outer
tail-streamers than females (usually 79–106 mm in males and 6884 mm
in females; tend to be darker chestnut on underparts. Bolcoloured
underwing grey and orange.
Adult female: Adult plumages are similar throughout year.
Bolcoloured underwing grey and cream.
Juvenile: (Juvenal plumage) are similar to adults but have
paler underparts and less forked tails with white band across tail
Similar Species: Cliff Swallow Petrochelidon fulva is similar
in voice and nesting habits, but shape and plumage are different.
Behavior: Flies at various heights from just above ground to
≥25 m. Flight consists of bursts of straight flight longer than
those of other swallows; birds frequently alter course slightly to
left or right. Flight may be circular when feeding over an insect
concentration, such as around cattle and birds are capable of
sharper turns and dives than other swallows. Increased
maneuverability is a consequence of the highly forked tail; outer
tail-streamers deflect leading edge of tail, resulting in higher
aerodynamic lift and allowing tighter turns. Goes to ground only to
collect mud, grass, or feathers for nest, to pick up bits of gravel
or (rarely) moribund insects, to sunbathe, or to seek refuge from
strong winds. Sidles along a wire, tree branch, or other perching
substrate using a sideways walk. When on ground, walks exclusively.
Habitat: The Barn Swallow has the distinction of being
perhaps the only northern temperate breeder that commonly winters in
South America and occasionally also breeds there during the boreal
winter; Barn Swallows have been reported nesting in small numbers in
Originally nesting primarily in caves, the Barn Swallow has almost
completely converted to breeding under the eaves of buildings or
inside artificial structures such as bridges and culverts. In North
America, this shift in nest sites began before European settlement
and was virtually complete by the mid-twentieth century; nowadays
natural nestings are rarely seen and usually reported in print if
they occur. As with other swallows that have shifted to nesting on
human-made structures, such as the Purple Martin (Progne subis),
Barn Swallows now sometimes nest in larger colonies than probably
occurred in natural settings.
As a consequence of
both its wide distribution and its nesting on accessible artificial
structures near people, the Barn Swallow has been studied
extensively throughout the world and especially in Europe. More
papers have been published on this species than on any other
swallow, and it is one of the most thoroughly studied birds in the
world. In addition, these swallows—not the more famous egrets—have
the distinction of having indirectly led to the founding of the
conservation movement in the United States: the destruction of Barn
Swallows for the millinery trade apparently prompted George Bird
Grinnell’s 1886 editorial in Forest and Stream that led to the
founding of the first Audubon Society
listed, COSEWIC n/a, Global G5 (1996). On balance, human activity
has had strongly positive effects on this species: construction of
artificial structures has provided abundant nesting sites, leading
to population size that is probably several orders of magnitude
greater than before European settlement of North America. Barn
Swallows are popular with people, and farmers often protect (rarely
persecute) the birds on their property. The species seems to have
adapted well to nesting in human-altered habitats in North America
The Barn Swallow has the longest migration of North American
swallows and numbers peak in August as juveniles disperse.
Capture rates (2010-2012; standardized as birds captured per
100 net hours) at Colony Farms correspondingly peak in
August and are lacking from Oct through April.