Blue-and-white Swallow

The blue-and-white swallow (Pygochelidon cyanoleuca) is a diminutive and agile passerine, with adults typically measuring 11–12 cm in length and weighing around 10 grams. They boast a striking dark blue upper body contrasted by a pristine white underbelly. Their underwings and the underside of their short, forked tail exhibit a darker, blackish hue. Juveniles present a more subdued palette, with brown upperparts, a buff tinge below, and a less pronounced fork in the tail.

Identification Tips

When identifying the blue-and-white swallow, look for its dark blue back and white underparts. The blackish underwings and tail underside are key features, along with its fluttery flight pattern. Juveniles can be distinguished by their brown upperparts and less forked tails.

Habitat

This species is a familiar sight in open areas such as villages, towns, farms, and forest clearings. In Central America, it is typically found in highland regions, but its habitat range extends from lowlands to elevations of up to 4,000 meters elsewhere.

Distribution

The blue-and-white swallow breeds from Nicaragua southward throughout South America, avoiding deserts and the Amazon Basin. The southern subspecies is known to migrate, spending winters as far north as Trinidad, where it is a regular visitor.

Behaviour

Outside of the breeding season, these swallows are often seen in small flocks. They exhibit a fluttery flight and are known to perch frequently on wires or branches.

Song & Calls

The blue-and-white swallow communicates with a buzzing call that can be transcribed as "dzzzhreeee."

Breeding

Both parents collaborate to construct a shallow straw nest within a variety of natural or man-made cavities, such as tree holes, rock crevices, and under bridges. Clutch size varies by region, with up to six white eggs in the southern range and two to three in the north. Incubation lasts approximately 15 days, and both parents feed the nestlings for 26 days until fledging. The young may continue to return to the nest to sleep for up to two months post-fledging, and the species may produce two broods per season.

Similar Species

The blue-and-white swallow can be confused with other swallows, but its distinctive coloration and habitat preferences help differentiate it from its congeners.

Diet and Feeding

Insects form the primary diet of the blue-and-white swallow, which it captures in mid-air. They are particularly attracted to areas where termites swarm.

Conservation Status

The blue-and-white swallow is classified as Least Concern by the IUCN. It has adapted well to human-altered landscapes, which have increased the availability of suitable habitats and food sources.