Atiu swiftlet

The Atiu swiftlet (Aerodramus sawtelli), also called Sawtell's swiftlet, is a small brown bird in the swift family Apodidae that is found only on Atiu, one of the Cook Islands. It was first described in 1974 by the ornithologist David Holyoak from a specimen collected at Anatakitaki Cave, and it is now placed in the genus Aerodramus with 27 other swiftlets. The species is named for Gordon Sawtell, a Cook Islands government official who helped Holyoak reach the island. Adults are mainly brown with a grey throat that contrasts with a darker brownish belly, and the type specimen had a wingspan of about 120 millimetres. The birds nest colonially in caves in the island's raised fossil coral limestone, known locally as makatea, building nests of plant material held together with saliva. Known nesting caves are Anatakitaki and Vaitupurangi, and they hunt flying insects such as wasps, moths and cockroaches over forest, fernland and farmland. Unlike other swiftlets it echolocates with single clicks only.