The Mangrove Swallow, Tachycineta albilinea, is a passerine bird with a penchant for coastal regions. This small, iridescent bird is adorned with blue-green upperparts and pure white underparts, including a distinctive white rump. Its tail and flight feathers are a contrasting blackish hue. A notable feature is the supraloral white streak, a white line near the eye, shared only with two other Tachycineta species.
Adults boast a slightly forked black tail and blackish flight feathers. The bill is a petite black, and the eyes are dark brown. Juveniles present with grey-brown upperparts and a white-washed underbelly. The sexes are similar, though females may have a marginally longer tail and shorter wings compared to males.
The Mangrove Swallow favors natural or artificial cavities near water for nesting, often choosing tree stumps or dead trees within close proximity to rivers or lakes.
This species is indigenous to Mexico and Central America, extending its range from Mexico through to Panama. It is typically found at elevations below 600 meters in Mexico and up to 1,000 meters in Costa Rica, though it generally prefers lower altitudes.
Outside of breeding season, the Mangrove Swallow can be seen in small flocks, gliding over water with rapid wingbeats. When breeding, it becomes territorial and is often observed alone or in pairs. It perches frequently near water between foraging flights.
The Mangrove Swallow's vocalizations include a soft trilling song, a rolled "jeerrrt" call, and a sharp alarm note to signal distress.
Breeding season sees this swallow as highly territorial and aggressive towards other hirundines. It typically lays two broods during a five-month period, with nests built low but above typical flood levels. Both parents feed the nestlings, which fledge after 23-27 days.
An aerial insectivore, the Mangrove Swallow hunts for large flying insects, such as dragonflies and bees. It forages close to the water's surface, often within 100 meters of its nest when feeding chicks, and may venture further when feeding itself.
The Mangrove Swallow is currently classified as Least Concern by the IUCN, with a population estimated to exceed 500,000 individuals. Despite a decreasing trend, the decline is not rapid enough to warrant a vulnerable status.