About Collocalia linchi Horsfield & F.Moore, 1854
This bird species, the cave swiftlet (Collocalia linchi), has shiny blackish-brown upperparts including the rump, with a greenish gloss; it sometimes appears black and hooded. Its chest is black, while the belly to flanks are pale grey with fine black speckles along the margins. It has rounded wing tips, a black underwing, and a black, rounded tail with a shallow notch. Unlike the very similar glossy swiftlet (Collocalia esculenta), this species lacks the white specks found on the tail of the glossy swiftlet. A key distinguishing feature between the two species is that the glossy swiftlet has a feather tuft on its hind toe, while the cave swiftlet has a naked hind toe. It measures 9 to 11.5 cm (3.5 to 4.5 in) in total length, and its call is a high-pitched "cheer-cheer". The cave swiftlet is native to Malaysia and Indonesia, occurring across the Sundaic region. Confirmed populations are found on Java, Madura Island, Bawean, Kangean Island, Nusa Penida, Bali, Lombok, parts of Sumatra, and on the western slopes of Mount Kinabalu in Sabah, Borneo. The only evidence of its occurrence in Malaysia comes from a single specimen held at the British Museum that is labelled "Molacca". Its natural habitat includes lowland and upland forest, as well as open woodland.
