Chestnut Forest Rail Rallicula rubra Scientific name definitions

18–23 cm; 3 males of subspecies klossi measured 84–91 (mean 87.7) g, 2 male telefolminensis were 71 and 76 g. Smallest species in genus Rallina. Reddish chestnut plumage of male makes confusion possible only with very similar but allopatric male Mayr's Forest Rail (Rallicula mayri), which is darker, with indistinct narrow black bars on tail. Female has back and upperwings black with small buff spots; resembles females of Forbes's Forest Rail (Rallicula forbesi) and Mayr's Forest Rail but has spotted upper mantle and lacks blackish barring on underparts; very similar to female White-striped Forest Rail (Rallicula leucospila) but lacks narrow black tail bars of this and the other two species. Subadult male has grey base to black bill, and dark wine-brown legs and feet; juvenile not described. Subspecies separated on: color of nape, tinged black in rubra; overall color, klossi palest chestnut; and biometrics, telefolminensis smallest.

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.

Possible subspecies subrubra (from Lake Habbema region of Snow Mts) has been merged with klossi because of overlapping measurements and lack of significant color differences. Three subspecies are recognized.

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.

Chestnut Forest Rail inhabits floors of montane forest interiors, at 1,500–3,050 m. At Tari Gap, it is found in mossy mixed lower montane beech forest. In areas of sympatry with Forbes's Forest Rail, the present species occurs at higher altitudes.

Uses a shrill, sharp krill or keowExternal link, which is often repeated many times; sometimes more squeaky. Duetting has been recorded, and duet calls  may become more rapid and sharper, kee or kek.

Chestnut Forest Rail lays from October–November, and either August or September, i.e. at the end of the period of highest rainfall. Apparently monogamous. Two adult males responded to one female's alarm call at a nest, suggesting the possibility of co-operative breeding. The nest is a large, domed structure of moss, grass, leaf skeletons, fibers, and fern fronds; it is lined with fine fibers, rootlets, and fragments of fern fronds; the base in this nest extended at one side into a ramp leading up to a side entrance. The nest is typically placed ca. 2 m up between frond bases in a Pandanus palm crown. Mean overall nest length is 38.5cm (with ramp measuring 15 cm) and height 25.5cm; mean nest chamber length is 21.5 cm and height is 13 cm. The species lays 1 large (27% of adult weight) egg only; incubation lasts at least 34 days, possibly over 37 days, the longest of any rallid. It is performed by both sexes, and the egg is often left to become cold; 2 newly hatched chicks weighed 13.4 and 14.4 g and had black down grizzled with russet or chestnut, dark brown iris, blackish legs and feet and blackish bill with white tip and egg tooth. One young chick was possibly killed by torrential rain at night.

Not globally threatened (Least Concern). Widespread in Irian Jaya, where subspecies rubra and klossi are apparently abundant; subspecies telefolminensis is apparently uncommon in the vicinity of Telefomin in the Victor Emmanuel and Hindenburg ranges, but the population common in Tari Gap forests is presumably also of this subspecies.