Bill moderate; nostrils large, oval, longitudinally elongate; legs and feet large, claws very long and nearly straight, claw of the middle toe as long as the culmen. "Wings rounded, the 1st primary equal to the 10th or a little longer ; secondaries as long as primaries. Tail short and rounded, of 12 feathers.
About fifteen species are known, ranging from the Friendly Islands and Australia to the Philippines and Celebes. One species is found far west of the other members of the genus in the Nicobar Islands.