The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like".
Rails are a large, cosmopolitan family of small- to medium-sized terrestrial and/or semi-amphibious birds. The family exhibits considerable diversity in its forms, and includes such ubiquitous species as the crakes, coots, and gallinule; other rail species are extremely rare or endangered. Many are associated with wetland habitats, some being semi-aquatic like waterfowl, but many more are wading birds or shorebirds. The ideal rail habitats are marsh areas, including rice paddies, and flooded fields or open forest. They are especially fond of dense vegetation for nesting. The rail family is found in every terrestrial habitat with the exception of dry desert, polar or freezing regions, and alpine areas. Members of Rallidae occur on every continent except Antarctica. Numerous unique island species are known.
The Inaccessible Island rail is a small bird species of the rail family, Rallidae. Endemic to Inaccessible Island in the Tristan Archipelago in the isolated south Atlantic, it is the smallest extant flightless bird in the world. The species was formally described by physician Percy Lowe in 1923 but had first come to the attention of scientists 50 years earlier. The Inaccessible Island rail's taxonomic affinities and origin were a long-standing mystery; in 2018 its closest relative was identified as the South American dot-winged crake, and it was decided that both species are best classified in the genus Laterallus.
Flightless birds are birds that cannot fly. They have, through evolution, lost the ability to fly. There are over 60 extant species, including the well-known ratites and penguins. The smallest flightless bird is the Inaccessible Island rail. The largest flightless bird, which is also the largest living bird in general, is the common ostrich.
Hutias are moderately large cavy-like rodents of the subfamily Capromyinae that inhabit the Caribbean islands. Most species are restricted to Cuba, but species are known from all of the Greater Antilles, as well as The Bahamas and (formerly) Little Swan Island off of Honduras.
The North Island takahē is an extinct species of flightless swamphen that was native to the North Island of New Zealand. It is closely related to the living South Island takahē.
The Rodrigues rail, also known as Leguat's gelinote or Leguat's rail, is an extinct species of the rail family that was endemic to the Mascarene island of Rodrigues. The bird was first documented from life by two accounts from 1691–93 and 1725–26. Subfossil remains were later discovered and correlated with the old accounts in 1874, and the species was named E. leguati in Leguat's honour. It is generally kept in its own genus, Erythromachus, but has sometimes been assigned to the genus Aphanapteryx along with its close relative the red rail of Mauritius; their relationship with other rails is unclear.
Gallirallus is a genus of rails that live in the Australasian-Pacific region. The genus is characterised by an ability to colonise relatively small and isolated islands and thereafter to evolve flightless forms, many of which became extinct following Polynesian settlement.
The New Caledonian rail is a large and drab flightless rail endemic to the island of New Caledonia in the Pacific. It is Critically Endangered, may have gone extinct many decades ago already, and if it still exists it is one of the least-known living bird species.
Porzana is a genus of birds in the crake and rail family, Rallidae. Its scientific name is derived from Venetian terms for small rails. The spotted crake is the type species.
The genus Dryolimnas comprises birds in the rail family. The Réunion rail, a member of this genus, became extinct in the 17th century. The white-throated rail of Aldabra is the last surviving flightless bird in the western Indian Ocean. They are mostly found on Malabar Island, but can also be found on Polymnieli Island and other islands.
Cabalus is a disputed Oceanian genus of birds in the family Rallidae. Both species placed in the genus here were previously considered part of the genus Gallirallus, one was alternatively placed in Tricholimnas alone or together with the Lord Howe woodhen, and the other was initially included in Rallus.
Dieffenbach's rail, known in the Moriori language as meriki or mehoriki, is an extinct flightless species of bird from the family Rallidae. It was endemic to the Chatham Islands.
The great Oʻahu rail or great Oʻahu crake is a little-known extinct bird species from Oʻahu, Hawaiʻi, attested only by a few subfossil bones. The holotype is a right tarsometatarsus found in a flooded sinkhole on the ʻEwa Plain near Barbers Point, the southwestern tip of Oʻahu.
The great Maui crake or great Maui rail is an extinct bird species from Maui, Hawaiian Islands, known only from subfossil bones. The holotype are the bones of one almost-complete skeleton, found in Auwahi Cave on the lower southern slope of Haleakalā at 1,145 m AMSL. Its first remains, however, were recovered in 1972 and/or 1974 from lower Waihoi Valley further east and less than half as far uphill.
Zapornia is a recently revalidated genus of birds in the rail family Rallidae; it was included in Porzana for much of the late 20th century. These smallish to tiny rails are found across most of the world, but are entirely absent from the Americas except as wind-blown stray birds. A number of species, and probably an even larger number of prehistorically extinct ones, are known only from small Pacific islands; several of these lost the ability to fly in the absence of terrestrial predators. They are somewhat less aquatic than Porzana proper, inhabiting the edges of wetlands, reedbelts, but also drier grass- and shrubland and in some cases open forest.
Hypotaenidia is a genus of birds in the family Rallidae. The genus is considered separate by the IOC and IUCN, while The Clements Checklist of Birds of the World / eBird consider the species to be part of Gallirallus. Since the mid-19th century, when these rather terrestrial birds were recognized to form a genus distinct from the decidedly aquatic Rallus, the validity of Hypotaenidia has been disputed.
