[3] The swiftlet is found in Guam as well as in Saipan and Aguiguan in the Northern Mariana Islands, and is locally extinct on Rota and Tinian.

[3] In its natural range the swiftlet builds shallow nests high on the interior walls and ceilings of limestone caves, including sites in zones of complete darkness, in colonies of a few to several hundred birds.

The swiftlets utter twittering and chirping sounds as well as the echolocation clicks used to navigate inside the nesting and roosting caves.

[3] The population on Guam declined because of predation by brown tree snakes and the use of agricultural pesticides, though it is believed to have subsequently increased to an estimated 900 individuals in 2006.

Proposed conservation measures include continued population monitoring and limiting cave disturbance, the prevention of the establishment of brown tree snakes in the Northern Marianas Islands, control of introduced mud dauber wasps and cockroaches where they damage nests, and the reintroduction of birds to Rota whence they were extirpated in the 1970s.