Black-capped Swallow is endemic to a small region in the highlands of northern Central America, from Mexico, south of the Isthmus of Tehuantepec, to Guatemala, El Salvador and Honduras. This swallow is a dark above and white below. The most distinctive aspect of this swallow is that it is small and dark and has a noticeably thick but well-forked tail. Highlighting the shape of the tail is the blackish vent, giving heightened prominence to the tail. The capped look is not obvious, although it is a white faced swallow with a dark cap, but because the cap is not of a different tone or color than the back, it does not looked very "capped" in the field. This swallow is relatively common in highlands where there is some oak-pine habitat, but its biology is poorly known. It appears to nest in cavities, although not cavities in trees. Instead it nests in holes in banks, crevices in rock, river banks, and even in buildings, particularly large and old stone masonry buildings where cracks and crevices are present. Nesting occurs from March to June in Guatemala. Little else is known about their biology. Black-capped Swallows appear to be resident and entirely insectivorous.