Invisible Rail
Encyclopedia
The Invisible Rail is a flightless species of bird in the family Rallidae
(rails), endemic
only to Halmahera
, north Maluku
, Indonesia
, especially its swamp forests, wetlands, and forest edges. The Invisible Rail is evaluated as Vulnerable
on the IUCN Red List
of Threatened Species. It is the world's smallest living flightless bird.
in 1860. It is the only member of monotypic genus Habroptila. It is known from only a handful of confirmed sightings and specimens—the most recent of which was in 2003. This species may be related to the New Guinea Flightless Rail
(Megacrex inepta). Alternate names include: Wallace's Rail, Drummer Rail (Soisa), Halmahera, Râle de Wallace (in French), Trommelralle (in German), and Rascón de Wallace (in Spanish).
. Both sexes are similar in color, dark slate-grey with darker brown wing and tail plumage
, bare red orbital skin, long reddish orange bill
and legs. The undersurface is somewhat lighter in color. It makes a low drumming sound with loud screams. It is superficially similar to the Purple Swamphen
(Porphyrio porphyrio) and Calayan Rail
(Gallirallus calayanensis). It is different from the Purple Swamphen in its markings, which has been recently discovered to also reside in Halmahera, though is has been known to reside elsewhere for thousands of years. It is different from the Calayan Rail in that it is larger and some markings are different. Confusion with both these species is likely. Of 26 bird species whose range is solely “Northern Maluku Endemic Bird Area”, the Invisible Rail is one of eight threatened species.
swamp forests and wetlands of Halmahera, Indonesia, favoring the edge habitats where swamp meets forests and clearings. Specific locales in that region where it has been sighted are Fanaha, Gani, Pasir Putih, Sondo, Tewe, and Weda Bay. There are also local reports of it living in the Kao sago swamp. It is classified as vulnerable with an estimated population of 2500–9999. Causes of this vulnerability are ongoing habitat loss from agriculture and aquaculture, fragmentation, predation, small population size, limited range
and hunting in some areas. Its stealthy, skulking behavior and dense habitat make it especially difficult to study in the wild. Consequently, it is poorly known and may even be more numerous than believed. Much of these sago swamps have been destroyed through sago extraction, predation, irrigation, conversion to wet rice fields, and fishpond development. Natives hunt this bird with snares and dogs.
(Pinguinus impennis), the Kakapo
(Strigops habroptilus) and some species of penguin. Breeding is in pairs and 4–5 chicks are hatched. Local people feel that during the dry season this bird leaves the forest.
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
(rails), endemic
Endemism in birds
An endemic bird area is a region of the world that contains two or more restricted-range species, while a "secondary area" contains one or more restricted-range species. Both terms were devised by Birdlife International....
only to Halmahera
Halmahera
Halmahera is the largest island in the Maluku Islands. It is part of the North Maluku province of Indonesia.Halmahera has a land area of 17,780 km² and a population in 1995 of 162,728...
, north Maluku
North Maluku
North Maluku is a province of northeastern Indonesia. It covers the northern part of the Maluku Islands, which are split between it and the province of Maluku. Maluku province used to cover the entire group...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, especially its swamp forests, wetlands, and forest edges. The Invisible Rail is evaluated as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
of Threatened Species. It is the world's smallest living flightless bird.
Taxonomy
The Invisible Rail was first classified by English zoologist George Robert GrayGeorge Robert Gray
George Robert Gray FRS was an English zoologist and author, and head of the ornithological section of the British Museum, now the Natural History Museum, in London for forty-one years...
in 1860. It is the only member of monotypic genus Habroptila. It is known from only a handful of confirmed sightings and specimens—the most recent of which was in 2003. This species may be related to the New Guinea Flightless Rail
New Guinea Flightless Rail
The New Guinea Flightless Rail , also known as the Papuan Flightless Rail, is a species of bird in the Rallidae family, in the monotypic genus Megacrex.-Distribution and habitat:It is found in Indonesia and Papua New Guinea...
(Megacrex inepta). Alternate names include: Wallace's Rail, Drummer Rail (Soisa), Halmahera, Râle de Wallace (in French), Trommelralle (in German), and Rascón de Wallace (in Spanish).
Description
It is a large, 330 to 400 mm (13 to 15.7 in) long, flightless railRallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
. Both sexes are similar in color, dark slate-grey with darker brown wing and tail plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
, bare red orbital skin, long reddish orange bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
and legs. The undersurface is somewhat lighter in color. It makes a low drumming sound with loud screams. It is superficially similar to the Purple Swamphen
Purple Swamphen
The Purple Swamphen , also known as the African Purple Swamphen, Purple Moorhen, Purple Gallinule, Pūkeko or Purple Coot, is a large bird in the family Rallidae . From its name in French, talève sultane, it is also known as the Sultana Bird...
(Porphyrio porphyrio) and Calayan Rail
Calayan Rail
The Calayan Rail is a flightless bird of the rail, moorhen, and coot family that inhabits Calayan Island in the Philippines. Though well-known to natives of the island as the "piding", it was first observed by ornithologist Carmela Española in May 2004 and the discovery officially announced on...
(Gallirallus calayanensis). It is different from the Purple Swamphen in its markings, which has been recently discovered to also reside in Halmahera, though is has been known to reside elsewhere for thousands of years. It is different from the Calayan Rail in that it is larger and some markings are different. Confusion with both these species is likely. Of 26 bird species whose range is solely “Northern Maluku Endemic Bird Area”, the Invisible Rail is one of eight threatened species.
Distribution and habitat
The Invisible Rail is native to the remotest and densest parts of the sagoSago
Sago is a starch extracted in the spongy center or pith, of various tropical palm stems, Metroxylon sagu. It is a major staple food for the lowland peoples of New Guinea and the Moluccas, where it is called saksak and sagu. A type of flour, called sago flour, is made from sago. The largest supply...
swamp forests and wetlands of Halmahera, Indonesia, favoring the edge habitats where swamp meets forests and clearings. Specific locales in that region where it has been sighted are Fanaha, Gani, Pasir Putih, Sondo, Tewe, and Weda Bay. There are also local reports of it living in the Kao sago swamp. It is classified as vulnerable with an estimated population of 2500–9999. Causes of this vulnerability are ongoing habitat loss from agriculture and aquaculture, fragmentation, predation, small population size, limited range
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
and hunting in some areas. Its stealthy, skulking behavior and dense habitat make it especially difficult to study in the wild. Consequently, it is poorly known and may even be more numerous than believed. Much of these sago swamps have been destroyed through sago extraction, predation, irrigation, conversion to wet rice fields, and fishpond development. Natives hunt this bird with snares and dogs.
Behaviour
Little is known of the Invisible Rail's life cycle. Its diet consists mainly of plant shoots, vegetation matters and insects. They also feed at open cuts of sago trunks. The call is drum-like sound (hence the common name drummer) with a loud scream. Flightlessness in birds is known to be related to changes in the pectoral girdle, flight feathers and body size, and was once speculated to also be related to brain size in birds. However, this has been proven to generally not be correlative to the flight capability of birds, except there is a correlation of flightlessness to small brain size in the Great AukGreat Auk
The Great Auk, Pinguinus impennis, formerly of the genus Alca, was a large, flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus, a group of birds that formerly included one other species of flightless giant auk from the Atlantic Ocean...
(Pinguinus impennis), the Kakapo
Kakapo
The Kakapo , Strigops habroptila , also called owl parrot, is a species of large, flightless nocturnal parrot endemic to New Zealand...
(Strigops habroptilus) and some species of penguin. Breeding is in pairs and 4–5 chicks are hatched. Local people feel that during the dry season this bird leaves the forest.