Blue swallows are small songbirds found in Africa. The adult birds have a highly lustrous dark metallic steel-blue appearance with long tail streamers, which are particularly noticeable in males. White feathers are visible on the rump and flanks when the birds are preening and especially during courtship. In poor light, Blue swallows appear almost black and therefore can be mistaken for Black saw-wing swallows which occur throughout their breeding range. Young Blue swallows start life a brownish-grey, acquiring their blue color as they mature.
Blue swallows breed from South Africa to Tanzania and winter north of Lake Victoria. Their breeding habitat includes montane grassland and in winter these birds prefer savanna and open grasslands with bushes and trees near wetlands.
Blue swallows are excellent flyers and use these skills to feed and attract mates. They are diurnal and social on the feeding grounds. Generally, swallows forage on the wing, but may on occasion snap prey off branches or on the ground. Their flight may be fast and involve a rapid succession of turns and banks when actively chasing fast-moving prey; less agile prey may be caught with a slower, more leisurely flight that includes flying in circles and bursts of flapping mixed with gliding. Swallows are able to produce many different calls or songs, which are used to express excitement, to communicate with others of the same species, during courtship, or as an alarm when a predator is in the area. The songs of males are related to the body condition of the bird and are presumably used by females to judge the physical condition and suitability for mating of males. Begging calls are used by the young when soliciting food from their parents. The typical song of swallows is a simple, sometimes musical twittering.
The mating system of Blue swallows is not well understood although these birds are known to exhibit co-operative breeding. They arrive on the breeding grounds at the end of September and construct cup-shaped nests from mud and grass on the inside of sinkhole cavities, aardvark burrows, and old mine shafts. The nests are lined with fine grass, animal hair, and white feathers. Normally, 3 white eggs are laid. They are incubated by the female for 14 days, and the chicks are fed for approximately 22 days until they fledge. The chicks hatch naked and with closed eyes. Once fledged, they spend the next couple of days around the nest site before disappearing. Most Blue swallows will rear a second brood before returning to the over-wintering grounds in April.
Blue swallows are threatened by the destruction of their habitat at both their breeding and wintering grounds. In some locations, they are often trapped for food and are vulnerable to changes in climate, severe weather, and pollution.
According to the IUCN Red List, the total Blue swallow population size is around 1,000-2,499 mature individuals which equate to 1,500-4,000 individuals. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List and its numbers today are decreasing.