Mossy-nest Swiftlet Aerodramus salangana Scientific name definitions

11·7–12 cm; 11·3 g. Medium-sized swiftlet with shallow tail-fork; uniform black-brown upperparts; uniform pale brown underparts. Race <em>natunae</em> averages longer-winged and has feathered tarsi; maratua and aerophilus smaller than other two races, maratua averaging paler than aerophilus which has deepest tail-fork (11–13%) and naked tarsi. From sympa­trics only safely distinguishable in hand or on nest; tarsal feathering variable, very light or lacking in nominate; light shaft streaking on underparts, lacking in some; grey-brown rami to back feathers. Nominate and race natunae both capable of echolocation.

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Feeds over variety of habitats adjacent to breeding caves . Apparently feeds at lower levels and closer to nest than sympatric A. maximus and for shorter periods, though both feed together at swarms. Particularly favours caves in primary forest.

Echolocating abilities have been confirmed for races salangana and natunae.

Certain active colony studied Mar, Padang Highlands, Sumatra, and further probable record of active colony in limestone cave with A. maximus in Apr in same highlands; at Niah, breeds over eight months from Sept to Apr. Colonial cave nester . Nest of vegetable matter agglutinated with sparse transparent saliva which remains soft and moist; requires support by ledge or similar irregularity. Two eggs, though one recorded; laid at interval of two days; both sexes brood but replacement of brooding bird does not occur during day; replacement and second clutches recorded; incubation period 19–27 days, mean 23. Fledging period where both young survived, 41–56 days, mean 48·5, compared with 41–55, mean 48, where only one survived after two hatched; young fed several times daily. Average breeding success 38% with 0·8 young fledged per breeding effort.

Not globally threatened (Least Concern). Believed to be uncommon on Java, though identification problems may disguise true status there (and potentially elsewhere, see Movements); otherwise locally abundant. Occurs in Gunung Mulu National Park, Sarawak; range might extend to S half of Borneo.