A small, common swiftlet found over a variety of habitats, even human habitation. Pale gray below with a darker throat and some dark speckling on the belly. Black above with blue gloss and a square tail that is dark under the base. Similar to Pygmy and Gray-rumped Swiftlets, but has a dark rump. Does not echolocate, so chooses well-lit nesting sites. Voice includes short, clicking flight calls.