Bird of the Month: Barn Swallow
By Andrew McCormick
Scientific Name: Hirundo rustica
Length 6.75 in
Wingspan 15 in
Weight 0.67 oz (19 g)
AOU Band code BARS
The Barn Swallow has made such good friends with human beings that it is now the most widespread and abundant swallow in the world. As humans have constructed buildings, bridges and culverts, Barn Swallows have expanded their range along with them (Brown and Brown). They are very familiar and well-loved by the general public with the possible exception of those who find their mud nests and messy droppings irksome and then destroy the nests (Bell and Kennedy). Barn Swallows are very comfortable around humans and will nest on sills above doors and windows and on open rafters in various structures including birdwatching blinds.
Their long wings attest to their long-distance migration which brings them to the Washington in late March and early April. They feed in flight and provide a wonderful service to humans by eating millions of flies, beetles, wasps, winged ants and other kinds of insects. They are commonly seen foraging over bodies of water and fields at lower altitudes than other swallow species (Brown and Brown). Barn Swallows tend to have longer straight flights than other swallows, but will also fly circular patterns when insect concentrations are higher such as around cattle (Brown and Brown). Birders will sometimes note that Barn Swallows will fly around them as they walk through fields.
The Barn Swallow is in the genus Hirundo, Latin for swallow, and the species name rusticarefers to its suitability for rural areas. The common name Barn is for one of its common nesting sites. Today, Barn Swallows are more likely to nest on a human-made structures than at more traditional sites such as in a cave or on a cliff face. Swallow is from the Anglo-Saxon swalewe, the name for this type of bird (Holloway).
The Barn Swallow’s nest is a cup of mud mixed with grass and lined with feathers (Kaufman). Typically 4-5 white eggs with brown-spots are deposited. Both parents incubate the eggs which hatch in a little more than two weeks, and both feed the young. Feeding is often augmented by non-breeding offspring from previous broods, thus creating a large family brood (Kaufman). First flight occurs in another three weeks. Some pairs will have a second brood and recent research has found that some pairs wintering in Argentina will have a winter brood (Brown and Brown). Barn Swallows require more territory than other swallows and most of the time will not nest in large colonies as some other species will.
The Barn Swallow has the most deeply forked tail of all the swallows. This can be an aid to identification, although juveniles will have less deeply forked tails. The Barn Swallow is well-researched and studies of European populations indicate that females select the males with more deeply forked tails. “Tail length tends to correlate with reproductive success, annual survival, propensity to engage in extra-pair copulation, parental effort…and other measures of fitness” (Brown and Brown). Barn Swallows have a wide-spread and stable population.