This swiftlet occurs on Palau. It is blackish brown above, grey below, and has a short, shallowly forked tail.
The upperparts are blackish brown and the underside is grey. The short tail is shallowly forked.
It catches insects in flight over highland ridges and gorges and tends to avoid deep forest.
It breeds in October and nests colonially in caves. The flat nest is made of moss and fine grass, and the clutch is one egg.
In the southern Palau Islands in 1945, many birds were observed flying in clearings and around cliffs.
The lower legs are unfeathered.
An extinction-risk assessment has not been added yet.