Endemic to the central highlands of Borneo, this small, fast flier can be difficult to identify in the field where overlap occurs with the more common Plume-toed Swiftlet (formerly a subspecies of Glossy Swiftlet). A typical “white-bellied swiftlet”, with a white belly, dusky throat, and glossy dark upperparts. Compared to Plume-toed, Bornean averages more green-glossed, but this can be difficult to see in a standard flight view. Most readily identified on nests, especially in the rocky upper reaches of mountains like Kinabalu (overlaps with Plume-toed at middle altitudes). Gives a high-pitched yipping chitter, especially when near the nest.