A small, fork-tailed, sooty-brown swallow with different plumages for the sexes: distinctive male has a pure white head and narrow black eye stripe; female has a mostly ashy head with white throat. Immature lacks white on the head. Pairs use clearings and edges of evergreen forest, open woodland, and cultivation. Resident in East Africa, but an intra-African breeding migrant in Zambia and Malawi between October and May. Superficially more similar to swifts than other swallows. Note the differences in flight style: flightier with deep wing beats and rapid changes of direction, as opposed to the more stiff-winged flight of swifts.