Barn Swallow Hirundo rustica
Hirundo is the Latin word for swallow, with rustica meaning “of the country.” The common name, swallow, may be derived from an Anglo-Saxon term for “cleft stick,” possibly referring to the Barn Swallow’s forked tail (though not all swallow species of North America have deeply notched tails). As implied by the common name, Barn Swallows frequently nest in open buildings such as barns and sheds, though they once nested in caves. Barn Swallows are the most widely distributed and most numerous swallow species in the world. They breed throughout North America (typically arriving in Maine in April), and winter in South America (departing Maine in September). They often flock and roost with other swallow species during migration.
Particularly colorful among swallow species, Barn Swallows have cinnamon-buff underparts and steel-blue upperparts, plus gray wings and tails. The tail feathers have white patches, with the outermost ones elongated and streamer-like. Although they occasionally glean prey from leaves and other surfaces, Barn Swallows mostly hunt on the wing, seeming to especially prefer large flies. While skimming a water surface, they bathe by dipping their bodies into water, and drink by scooping up water with their bills.
Ideal habitat on the breeding ground would be open country with low vegetation, some nearby water, and wires or roof ridges for perching. Almost any open structure could host a nest, and an especially large barn or stable might contain a dozen or more families. Cup-shaped nests made of mud mixed with grass are built under an overhang/roof, often on a horizontal ledge against a wall, but sometimes attached to a wall without underneath support. Nests are lined with fine grass, horsehair, and/or feathers, and there are usually 4-5 eggs. Incubation lasts roughly two weeks, and both parents incubate, although the female does the greater share.
Barn Swallows hatch naked except for tufts of grayish down. Their eyes begin to open at about 1 week, and a bit later, as feathers mature, nestlings begin flapping and preening. Both parents feed the youngsters, but brooding appears to be mostly the job of the female. Young Barn Swallows fledge at about 3 weeks of age, and may return to the nest to sleep for the first few days after that. Fledglings are fed by the parents for several days, at first while they are perching, but later in midair. Family groups break up after 1-2 weeks.
Nestling mortality may result from lack of insects in cold, rainy spells, but youngsters may become orphaned if they fall from overcrowded or tilting/slipping nests, or of course if the entire nest falls. Human-related activities that may interfere with breeding success include demolitions or structural repairs of barns, and appropriation of nest areas for hay storage.
Despite their abundance world-wide, there have been population declines in northern parts of the breeding range, and the Barn Swallow is a Species of Special Concern in Maine.
More information about their natural history may be found at https://www.allaboutbirds.org/guide/Barn_Swallow