Tenggara Swiftlet Collocalia sumbawae

A tiny swift with dark plumage except for the off-white underside from the lower breast down. Tail looks square, only sometimes showing a very marginal tail notch. Aerial and gregarious, gathering in flocks over a variety of habitats, both open and forested. Restricted to the western Lesser Sundas, where it only overlaps with one other similar species, White-nest Swiftlet. Tenggara Swiflet is smaller with a white underside, unlike that species.