Nidification of the Chestnut Forest-Rail Rallina rubra (Rallidae) in Papua New Guinea and a Review of Rallina Nesting Biology

Abstract

Nests, eggs and chicks of the Chestnut Forest-Rail Rallina rubra are described for the first time, from Tan Gap, Southern Highlands Province, Papua New Guinea. The nest is a large globular or domed structure of moss, leaves and ferns with a side entrance, typically placed some 2 m high in a pandanus palm crown (n = 20). The clutch is a single egg, unlike other rail clutches, and the egg is very large, being proportionately greater in mass to the bird than in any other rail so documented. Both sexes incubate but eggs are often left to become cold. Incubation in one nest was at least 34-37 days, being much longer than the incubation period of the only congener or of any other rail known. Nesting biology of RaIlina spp. is reviewed.