A rare and little-known swiftlet found very locally in the lower mountains of New Guinea; exact range very poorly known. Fairly large swiftlet, gray-brown above with no pale rump and uniform grayish below. Roosts under rock-overhangs of mountain streams. Very little known about its biology. Similar to Mountain & Three-toed Swiftlets but Bare-legged Swiftlet is slightly larger in size with a big-headed appearance. Difficult to separate in the field. Vocalizations unknown.