Rallo russante

Identificazione

The snoring rail is 30 cm (12 in) long and weighs 143–160 g (5.0–5.6 oz). It is flightless, with short wings, a very short tail and strong legs and feet. The back and the underparts from the forecrown to the breast are grey, apart from a white chin, and the sides and rear of the neck are deep orange-red. Most of the rest of the upperparts are brown, and the belly, flanks, and undertail have white barring. The male has black legs, a yellow iris and a brown and greenish down-curved bill. The female is similar but has a brighter hindneck colour, less white on the chin, a red iris, a cream and reddish bill and blue-grey legs. Immature and juvenile plumages are undescribed. Visual confusion with sympatric rails is unlikely. The blue-faced rail is similar in size, but is chestnut above and black below, and the buff-banded rail has strongly marked upperparts, breast, and head. The slaty-breasted rail is smaller and has barred upperparts.<p>The call, given frequently, is a short wheez followed by a distinctive snoring ee-orrrr. A deep hmmmm sound has also been recorded.

Tassonomia

The rails are a large and very widespread family, with nearly 150 species. They are small to medium-sized, terrestrial or wetland birds, and their short bodies are often flattened laterally to help them move through dense vegetation. Island species readily become flightless; of 53 extant or recently extinct taxa restricted to islands, 32 have lost the ability to fly.<p>The snoring rail was first classified as Rallus plateni by German ornithologist August Wilhelm Heinrich Blasius in 1886, but was moved to its current monotypic genus Aramidopsis by English zoologist Richard Bowdler Sharpe in 1893. Following Taylor (1998), it was considered to be more similar to the Inaccessible Island and white-throated rails than to members of the genus Rallus, but a 2012 mitochondrial gene study suggests that it should actually be placed in Gallirallus, with Lewin's rail and the slaty-breasted rail as its closest relatives.<p> Aramidopsis derives from the genus name of the limpkin, Aramus and the Greek suffix opsis, "resembling". Although the rail shares the origin of its name with the South American Aramides species, its distinctive bill, thick legs and barred lower belly distinguish it from that group. The species name plateni commemorates Carl Constantin Platen, a German doctor who collected birds and butterflies in the Malay Archipelago and gave Blasius his specimen of the rail. The common name refers to the rail's distinctive call, and was given to the bird as der Vogel Schnarch (the snoring bird) by German entomologist Gerd Heinrich when he rediscovered the species in 1932.

Nome scientifico

Aramidopsis plateni

Autorità

(Blasius, W, 1886)

Ordine

Gruiformi

Famiglia

Rallidae

Genere

Aramidopsis

Areale e habitat

The species is an uncommon Indonesian endemic of lowland and hill forests in northern, north central and southeastern Sulawesi. Another population was found on Buton island in 1995.<p>The typical habitat of this species is dense vegetation in wet areas. This may include impenetrable bamboo and liana in forests, rattan in regrown forests, or elephant grass and bushes on the hillsides of Minahassa Peninsula. Claims of the species occurring in rice fields are believed to be due to confusion with the buff-banded rail. The snoring rail occurs from sea level to 1,300 m (4,300 ft).

Migrazione

Resident species

Comportamento

Its inaccessible habitat and sparse distribution means that little is known about this species. A few birds were shot by Platen and another expedition led by Paul Sarasin and his second cousin, Fritz, between 1893 and 1898, but the rail was then not seen for more than thirty years until Heinrich found it almost at the end of a two-year survey of Sulawesi, then known as Celebes. He described it as "the most priceless catch that I have ever hunted or will hunt". More than a decade later, Dutch ornithologist Louis Coomans de Ruiter also took a year to find the rail, despite concentrating on known suitable habitat. There were then no documented sightings until birds were observed in 1983 and 1989. Sight records remain infrequent, and only about ten specimen corpses have been studied.<p>The snoring rail catches crabs in highland streams, and these crustaceans may be a major dietary item. It also forages in muddy areas, and has been recorded as consuming lizards. Nothing is known of its breeding behaviour other than a report of an adult seen feeding with two chicks in August 1983, but the original report gives no details of the claimed sighting.

Conservazione

Tendenza della popolazione

declining