Rallidae
Encyclopedia
The rails, or Rallidae, are a large cosmopolitan
family
of small to medium-sized bird
s. The family exhibits considerable diversity
and the family also includes the crakes, coots, and gallinules. Many species
are associated with wetland
s, although the family is found in every terrestrial
habitat
except dry desert
s, polar
regions and alpine
areas above the snow line
.
Members of the Rallidae are found on every continent except Antarctica. There are numerous island species. The most common habitats are marsh
land or dense forest. Rails are especially fond of dense vegetation.
in damp environments near lake
s, swamp
s, or river
s. Reed bed
s are a particularly favoured habitat. They are omnivorous
, and those that migrate
do so at night: most nest
in dense vegetation. In general, they are shy and secretive birds, and are difficult to observe.
Most species walk and run vigorously on strong legs, and have long toes which are well adapted to soft, uneven surfaces. They tend to have short, rounded wings and although they are generally weak fliers
, they are, nevertheless, capable of covering long distances.
Island species often become flightless
, and many of them are now extinct
following the introduction of terrestrial predators
such as cat
s, rat
s and pig
s.
Many reedbed species are secretive (apart from loud calls), crepuscular
, and have laterally flattened bodies. In the Old World
, long-billed species tend to be called rails and short-billed species crakes. North America
n species are normally called rails irrespective of bill length. The smallest of these is the Swinhoe's Rail
, at 13 cm (5 inches) and 25 grams.
The larger species are also sometimes given other names. The black coots are more adapted to open water than their relatives, and some other large species are called gallinules and swamphens. The largest of this group is the Takahē
, at 65 cm (26 inches) and 2.7 kg (6 lbs).
The rails have suffered disproportionally from human changes to the environment and it is estimated that several hundred species of island rail have become extinct because of this. Several island species of rail remain endangered
and conservation
organisations and governments continue to work to prevent their extinction.
The rails are a fairly homogeneous family of small to medium sized ground living birds. They vary in length from 12 cm to 63 cm and in weight from 20 g to 3000 g. Some species have long necks and in many cases they are laterally compressed. The bill is the most variable feature within the family: in some species it is longer than the head (like the Clapper Rail
of the Americas), in others it may be short and wide (as in the coot
s), or massive (as in the purple gallinules
). A few coots and gallinules have a "frontal shield", which is a fleshy rearward extension of the upper bill. The most complex frontal shield is found in the Horned Coot
.
Rails exhibit very little sexual dimorphism
in either plumage
or size.
of those Rallidae able to fly, while not very powerful, can be sustained for long periods of time and many species undertake annual migrations
. The weakness of their flight, however, means that they are easily blown off course and thus are common vagrants
, a characteristic that has led them to colonize many isolated oceanic islands. Furthermore, these birds often prefer to run rather than fly, especially when in dense habitat. Some are also flightless at some time during their moult
period.
Many island rails are flightless because small island habitats without threatening predators often eliminate the need to fly or move long distances. Flight
makes intense demands, with the keel
and flight muscles taking up to a quarter of a bird's weight in Rallidae species. Reducing the flight muscles, along with the corresponding lowering in metabolic
demands, reduces the flightless rail's energy expenditures. For this reason flightlessness makes it easier to survive and colonize an island where resources may be limited. Flightlessness can evolve extremely rapidly in island rails; it took as little as 125,000 years for the Laysan Rail
to lose the power of flight and evolve the reduced, stubby wings only useful to keep balance when running quickly.
s, as well as fruit or seedlings. A few species are primarily vegetarian
.
The calls
of Rallidae species vary and are often quite loud. Some are whistle-like or squeak-like, while others are "unbirdlike". Loud calls are useful in dense vegetation or at night where it is difficult to see another member of the species. Some calls are territorial
.
, although polygyny
and polyandry
have been reported.
Most often, there are five to ten eggs
. Clutch
es as small as one or as large as fifteen eggs are known.
Egg clutches may not always hatch at the same time. Chicks become mobile after a few days. They will often remain dependent on their parents until fledging, which happens at around one month of age.
and their eggs collected for food. The Wake Island Rail
was hunted to extinction by the starving Japanese garrison after the island was cut off from supply during World War II
.
At least two species - the Common Moorhen
and the American Purple Gallinule
- have been considered pests.
, many island species have been unable to cope with introduced species. The most dramatic human caused extinctions occurred in the Pacific Ocean
as people colonised the islands of Melanesia
, Polynesia
and Micronesia
, during which an estimated 750-1800 species of bird went extinct, half of which were rails. Some species which came close to extinction, such as the Lord Howe Woodhen
, and the Takahē
, have made modest recoveries due to the efforts of conservation organisations. The Guam Rail
came perilously close to extinction when Brown tree snake
s were introduced to Guam
but some of the last remaining individuals were taken into captivity and are breeding well, although attempts to reintroduce it have met with mixed results.
s and bustard
s, as well as several smaller families of usually "primitive" mid-sized amphibious birds, to make up the order Gruiformes
. The alternative Sibley-Ahlquist taxonomy
, which has been widely accepted in America, raises the family to ordinal level as the Ralliformes. Given the uncertainty about gruiform monophyly
, this may or may not be correct; it certainly seems more justified than most of the Sibley-Ahlquist proposals. On the other hand, such a group would probably also include the Heliornithidae
(finfoots and Sungrebe), an exclusively tropical
group that is somewhat convergent
with grebe
s, and usually united with the rails in the Ralli.
.jpg)
.jpg)
Additionally, there are many prehistoric rails of extant genera, known only from fossil
or subfossil remains, such as the Ibiza Rail
(Rallus eivissensis). These have not been listed here; see the genus accounts and the articles on fossil and Late Quaternary prehistoric birds for these species.
The undescribed Fernando de Noronha Rail, genus and species undetermined, probably survived to historic times.
and see genus accounts
species of long-extinct prehistoric rails are richly documented from the well-researched formations of Europe
and North America
, as well from the less comprehensively studied strata elsewhere:
The presumed scolopacid wader
Limosa gypsorum (Montmartre Late Eocene of France) is sometimes considered a rail and then placed in the genus Montirallus.
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of small to medium-sized bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. The family exhibits considerable diversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
and the family also includes the crakes, coots, and gallinules. Many species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are associated with wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s, although the family is found in every terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
except dry desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s, polar
Polar climate
Regions with a polar climate are characterized by a lack of warm summers . Regions with polar climate cover over 20% of the Earth. The sun shines 24 hours in the summer, and barely ever shines at all in the winter...
regions and alpine
Alpine climate
Alpine climate is the average weather for a region above the tree line. This climate is also referred to as mountain climate or highland climate....
areas above the snow line
Snow line
The climatic snow line is the point above which snow and ice cover the ground throughout the year. The actual snow line may seasonally be significantly lower....
.
Members of the Rallidae are found on every continent except Antarctica. There are numerous island species. The most common habitats are marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
land or dense forest. Rails are especially fond of dense vegetation.
Ecology
The most typical family members occupy dense vegetationVegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
in damp environments near lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, or river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s. Reed bed
Reed bed
Reed beds are natural habitats found in floodplains, waterlogged depressions andestuaries. Reed beds are part of a succession from young reed colonising open water or wet ground through a gradation of increasingly dry ground...
s are a particularly favoured habitat. They are omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
, and those that migrate
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
do so at night: most nest
Bird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
in dense vegetation. In general, they are shy and secretive birds, and are difficult to observe.
Most species walk and run vigorously on strong legs, and have long toes which are well adapted to soft, uneven surfaces. They tend to have short, rounded wings and although they are generally weak fliers
Bird flight
Flight is the main mode of locomotion used by most of the world's bird species. Flight assists birds while feeding, breeding and avoiding predators....
, they are, nevertheless, capable of covering long distances.
Island species often become flightless
Flightless bird
Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...
, and many of them are now extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
following the introduction of terrestrial predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
such as cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s and pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s.
Many reedbed species are secretive (apart from loud calls), crepuscular
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
, and have laterally flattened bodies. In the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
, long-billed species tend to be called rails and short-billed species crakes. North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n species are normally called rails irrespective of bill length. The smallest of these is the Swinhoe's Rail
Swinhoe's Rail
The Swinhoe's Rail is a species of bird in the Rallidae family.It is found in China, Japan, North Korea, South Korea, and Russia.Its natural habitats are swamps, freshwater lakes, freshwater marshes, and arable land...
, at 13 cm (5 inches) and 25 grams.
The larger species are also sometimes given other names. The black coots are more adapted to open water than their relatives, and some other large species are called gallinules and swamphens. The largest of this group is the Takahē
Takahe
The Takahē or South Island Takahē, Porphyrio hochstetteri is a flightless bird indigenous to New Zealand and belonging to the rail family. It was thought to be extinct after the last four known specimens were taken in 1898...
, at 65 cm (26 inches) and 2.7 kg (6 lbs).
The rails have suffered disproportionally from human changes to the environment and it is estimated that several hundred species of island rail have become extinct because of this. Several island species of rail remain endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
and conservation
Bird conservation
Bird conservation is a field in the science of conservation biology related to threatened birds. Humans have had a profound effect on many bird species...
organisations and governments continue to work to prevent their extinction.
Morphology
Clapper Rail
The Clapper Rail is a member of the rail family, Rallidae. Some researchers believe that this bird and the similar King Rail are a single species; the two birds are known to interbreed.-Distribution and habitat:...
of the Americas), in others it may be short and wide (as in the coot
Coot
Coots are medium-sized water birds that are members of the rail family Rallidae. They constitute the genus Fulica. Coots have predominantly black plumage, and, unlike many of the rails, they are usually easy to see, often swimming in open water...
s), or massive (as in the purple gallinules
Porphyrio
Porphyrio is the swamphen genus of birds in the rail family. It includes some smaller species which are usually called "purple gallinules", and which are sometimes separated as genus Porphyrula or united with the gallinules proper in Gallinula. There are two living species of swamphen, the...
). A few coots and gallinules have a "frontal shield", which is a fleshy rearward extension of the upper bill. The most complex frontal shield is found in the Horned Coot
Horned Coot
The Horned Coot is a species of bird found at lakes in the altiplano of north-western Argentina, south-western Bolivia, and north-eastern Chile. It is almost entirely restricted to altitudes of 3000-5200 m.a.s.l., but has occasionally been recorded at lower altitudes...
.
Rails exhibit very little sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
in either 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...
or size.
Flight and flightlessness
The wings of all rails are short and rounded. The flightBird flight
Flight is the main mode of locomotion used by most of the world's bird species. Flight assists birds while feeding, breeding and avoiding predators....
of those Rallidae able to fly, while not very powerful, can be sustained for long periods of time and many species undertake annual migrations
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
. The weakness of their flight, however, means that they are easily blown off course and thus are common vagrants
Vagrancy (biology)
Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
, a characteristic that has led them to colonize many isolated oceanic islands. Furthermore, these birds often prefer to run rather than fly, especially when in dense habitat. Some are also flightless at some time during their moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
period.
Many island rails are flightless because small island habitats without threatening predators often eliminate the need to fly or move long distances. Flight
Bird flight
Flight is the main mode of locomotion used by most of the world's bird species. Flight assists birds while feeding, breeding and avoiding predators....
makes intense demands, with the keel
Keel (bird)
A keel or carina in bird anatomy is an extension of the sternum which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight...
and flight muscles taking up to a quarter of a bird's weight in Rallidae species. Reducing the flight muscles, along with the corresponding lowering in metabolic
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
demands, reduces the flightless rail's energy expenditures. For this reason flightlessness makes it easier to survive and colonize an island where resources may be limited. Flightlessness can evolve extremely rapidly in island rails; it took as little as 125,000 years for the Laysan Rail
Laysan Rail
The Laysan Rail or Laysan Crake was a tiny inhabitant of the Northwest Hawaiian Island of Laysan. This small island was and still is an important seabird colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat loss by domestic rabbits, and ultimately...
to lose the power of flight and evolve the reduced, stubby wings only useful to keep balance when running quickly.
Behavior and ecology
In general, members of Rallidae are omnivorous generalists. Many species will eat invertebrateInvertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, as well as fruit or seedlings. A few species are primarily vegetarian
Vegetarianism
Vegetarianism encompasses the practice of following plant-based diets , with or without the inclusion of dairy products or eggs, and with the exclusion of meat...
.
The calls
Bird song
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs are distinguished by function from calls.-Definition:The distinction between songs and calls is based upon...
of Rallidae species vary and are often quite loud. Some are whistle-like or squeak-like, while others are "unbirdlike". Loud calls are useful in dense vegetation or at night where it is difficult to see another member of the species. Some calls are territorial
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
.
Reproduction
The breeding behavior of many Rallidae species are poorly understood or unknown. Most are thought to be monogamousMonogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
, although polygyny
Polygyny
Polygyny is a form of marriage in which a man has two or more wives at the same time. In countries where the practice is illegal, the man is referred to as a bigamist or a polygamist...
and polyandry
Polyandry
Polyandry refers to a form of marriage in which a woman has two or more husbands at the same time. The form of polyandry in which a woman is married to two or more brothers is known as "fraternal polyandry", and it is believed by many anthropologists to be the most frequently encountered...
have been reported.
Most often, there are five to ten eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. Clutch
Clutch
A clutch is a mechanical device which provides for the transmission of power from one component to another...
es as small as one or as large as fifteen eggs are known.
Egg clutches may not always hatch at the same time. Chicks become mobile after a few days. They will often remain dependent on their parents until fledging, which happens at around one month of age.
Rallidae and humans
Some of the larger, more abundant rails are huntedHunting
Hunting is the practice of pursuing any living thing, usually wildlife, for food, recreation, or trade. In present-day use, the term refers to lawful hunting, as distinguished from poaching, which is the killing, trapping or capture of the hunted species contrary to applicable law...
and their eggs collected for food. The Wake Island Rail
Wake Island Rail
The extinct Wake Island Rail was a flightless rail and the only native land bird on the Pacific atoll of Wake. It was found on the islands of Wake and Wilkes, but not on Peale, which is separated from the others by a channel of about 100 meters.-Description:The adult bird had a length of . The...
was hunted to extinction by the starving Japanese garrison after the island was cut off from supply during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Common Moorhen
The Common Moorhen is a bird in the Rallidae family with an almost worldwide distribution. The North and South American Committees of the AOU and the IOC have voted on or before July 2011 to split the American forms into a new species Common Gallinule, however, no other committee has voted to...
and the American Purple Gallinule
American Purple Gallinule
The American Purple Gallinule is a "swamp hen" in the rail family Rallidae.A medium-sized rail with big yellow feet, purple-blue plumage with a green back, and red and yellow bill. It has a pale blue forehead shield and white undertail.Juveniles are brown overall with a brownish olive back...
- have been considered pests.
Threats and conservation
Due to their tendencies towards flightlessnessFlightless bird
Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...
, many island species have been unable to cope with introduced species. The most dramatic human caused extinctions occurred in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
as people colonised the islands of Melanesia
Melanesia
Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...
, Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
and Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
, during which an estimated 750-1800 species of bird went extinct, half of which were rails. Some species which came close to extinction, such as the Lord Howe Woodhen
Lord Howe Woodhen
The Lord Howe Woodhen, Gallirallus sylvestris, also known as the Lord Howe Island Woodhen or Lord Howe Rail, is a flightless bird of the rail family . It is endemic to Lord Howe Island off the Australian coast. It is a small olive brown bird, with a short tail and a downcurved bill...
, and the Takahē
Takahe
The Takahē or South Island Takahē, Porphyrio hochstetteri is a flightless bird indigenous to New Zealand and belonging to the rail family. It was thought to be extinct after the last four known specimens were taken in 1898...
, have made modest recoveries due to the efforts of conservation organisations. The Guam Rail
Guam Rail
The Guam Rail, Gallirallus owstoni, is a flightless bird, endemic to Guam. The Guam Rail, which is locally known as the Ko'ko' in Chamorro, disappeared from southern Guam in the early 1970s and was extirpated from the entire island by the late 1980s...
came perilously close to extinction when Brown tree snake
Brown tree snake
The brown tree snake is an arboreal rear-fanged colubrid snake native to eastern and northern coastal Australia, Papua New Guinea, and a large number of islands in northwestern Melanesia....
s were introduced to Guam
Guam
Guam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...
but some of the last remaining individuals were taken into captivity and are breeding well, although attempts to reintroduce it have met with mixed results.
Systematics and evolution
The family Rallidae has traditionally been grouped with two families of larger birds, the craneCrane (bird)
Cranes are a family, Gruidae, of large, long-legged and long-necked birds in the order Gruiformes. There are fifteen species of crane in four genera. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back...
s and bustard
Bustard
Bustards, including floricans and korhaans, are large terrestrial birds mainly associated with dry open country and steppes in the Old World...
s, as well as several smaller families of usually "primitive" mid-sized amphibious birds, to make up the order Gruiformes
Gruiformes
The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like"....
. The alternative Sibley-Ahlquist taxonomy
Sibley-Ahlquist taxonomy
The Sibley-Ahlquist taxonomy is a bird taxonomy proposed by Charles Sibley and Jon Edward Ahlquist. It is based on DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s....
, which has been widely accepted in America, raises the family to ordinal level as the Ralliformes. Given the uncertainty about gruiform monophyly
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, this may or may not be correct; it certainly seems more justified than most of the Sibley-Ahlquist proposals. On the other hand, such a group would probably also include the Heliornithidae
Heliornithidae
The Heliornithidae are a small family of tropical birds with webbed lobes on their feet like those of grebes and coots. The family overall are known as finfoots, although one species is known as a Sungrebe. The family is composed of three species in three genera.-Description:Finfoots resemble...
(finfoots and Sungrebe), an exclusively tropical
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
group that is somewhat convergent
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
with grebe
Grebe
A grebe is a member of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter...
s, and usually united with the rails in the Ralli.
Extant (living) genera
- Himanthornis - Nkulengu RailNkulengu RailThe Nkulengu Rail is a species of bird in the Rallidae family. It is monotypic within the genus Himantornis....
- Sarothrura - flufftails (9 species)
- CanirallusCanirallusCanirallus is a genus of bird in the rail family, Rallidae. This genus includes one species from wet forests in West and Middle Africa, and two species from forests in Madagascar.-Species:...
(3 species) - CoturnicopsCoturnicopsCoturnicops is a genus of bird in the Rallidae family. It contains the following species:* Swinhoe's Rail, Coturnicops exquisitus* Yellow Rail, Coturnicops noveboracensis* Speckled Crake, Coturnicops notatus...
(3 species) - Micropygia - Ocellated CrakeOcellated CrakeThe Ocellated Crake is a species of bird in the Rallidae family. It belongs to the monotypic genus Micropygia....
- RallinaRallinaRallina is a genus of bird in the rail family, Rallidae. It contains eight species found in forest and marshland in Asia and Australasia. They are 18–34 cm long and mainly chestnut or brown, often with black and white markings....
- forest rails (8 species) - AnurolimnasAnurolimnasAnurolimnas is a genus of birds in the Rallidae family.It contains the following species:* Chestnut-headed Crake * Russet-crowned Crake * Black-banded Crake...
(3 species) - Atlantisia - Inaccessible Island RailInaccessible Island RailThe Inaccessible Island Rail is a small bird of the rail family, Rallidae. It is the only species in its genus. It is found only on Inaccessible Island in the Tristan Archipelago, and is notable for being the smallest extant flightless bird in the world...
- LaterallusLaterallusLaterallus is a genus of birds in the rail family Rallidae. These small, relatively short-billed terrestrial rails are found among dense vegetation near water in the Neotropics, although a single species, the Black Rail, also occurs in the United States....
(10 species) - NesoclopeusNesoclopeusNesoclopeus is a genus of birds in the Rallidae family.It contains the following species:* Bar-winged Rail, Nesoclopeus poecilopterus - extinct * Woodford's Rail, Nesoclopeus woodfordi...
(1 living species, 1 recently extinct) - GallirallusGallirallusGallirallus is a genus that contains about a dozen living species of rails that live in the Australasian-Pacific region. Many of these, including the most well-known one - the bold and inquisitive weka of New Zealand - are flightless or nearly so; others, such as the Buff-banded Rail, can go for...
- Austropacific rails (11-12 living species, 3-5 recently extinct) - RallusRallusRallus is a genus of wetland birds of the rail family. Sometimes, the genera Lewinia and Gallirallus are included in it. Six of the species are found in the Americas, and the three species found in Eurasia, Africa and Madagascar are very closely related to each other, suggesting they are descended...
- typical rails (some 9 living species) - LewiniaLewiniaLewinia is a genus of bird in the Rallidae family. It contains the following species:* Lewin's Rail, Lewinia pectoralis* Brown-banded Rail, Lewinia mirifica* Auckland Rail, Lewinia muelleri...
(3 species; sometimes included in Rallus) - DryolimnasDryolimnasThe 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....
(1 living species, 1 recently extinct) - Crecopsis - African CrakeAfrican CrakeThe African Crake is a bird in the rail family that breeds in most of sub-Saharan Africa away from the arid south and southwest. It is seasonally common in most of its range other than the rainforests and areas that have low annual rainfall...
(sometimes included in Crex) - Crex - Corn CrakeCorn CrakeThe Corn Crake, Corncrake or Landrail is a bird in the rail family. It breeds in Europe and Asia as far east as western China, and migrates to Africa for the winter...
- Rougetius - Rouget's RailRouget's RailThe Rouget's Rail is a species of bird in the Rallidae family. It is the only member of the genus Rougetius...
- Aramidopsis - Snoring RailSnoring RailThe Snoring Rail, Aramidopsis plateni also known as Celebes Rail or Platen's Rail is a medium-sized, approximately 30 cm long, flightless rail. It is the only member of the monotypic genus Aramidopsis. Both sexes are quite similar, having gray plumage, white chins, brown wings, short tails and...
- AramidesAramidesAramides is a genus of birds in the Rallidae family.It contains the following species:* Red-throated Wood Rail, Aramides gutturalis - doubtful species; extinct * Little Wood Rail, Aramides mangle...
- wood rails (8-9 living species, possibly 1 recently extinct) - Amaurolimnas - Uniform CrakeUniform CrakeThe Uniform Crake is a species of bird in the Rallidae family, the only member of the genus Amaurolimnas. It is found widely, but locally, in swampy forests and wetlands of southern Mexico, and Central and South America...
- GymnocrexGymnocrexGymnocrex is a genus of bird in the rail family, Rallidae.It contains the following species:* Bare-eyed Rail, Gymnocrex plumbeiventris* Blue-faced Rail or Bald-faced Rail, Gymnocrex rosenbergii* Talaud Rail, Gymnocrex talaudensis...
(3 species) - AmaurornisAmaurornisAmaurornis is a genus of birds in the Rallidae family.It contains the following species:* Brown Crake, * Plain Bush-hen, * Isabelline Bush-hen,...
- bush-hens (9 species) - PorzanaPorzanaPorzana is a genus of birds in the crake or rail family, Rallidae. It has a global distribution, contains 13 living species, and 4-5 recently extinct ones...
- typical crakes (13 living species, 4-5 recently extinct) - Aenigmatolimnas - Striped CrakeStriped CrakeThe Striped Crake is a species of bird in the Rallidae family. It is the only species in the genus Aenigmatolimnas....
- Cyanolimnas - Zapata RailZapata RailThe Zapata Rail is a 29 cm long, dark-coloured rail, the only member of the monotypic genus Cyanolimnas. It has brown upperparts, greyish-blue underparts, a red-based yellow bill, white undertail coverts, and red eyes and legs. Its short wings render it almost flightless...
- NeocrexNeocrexNeocrex is a genus of bird in the Rallidae family. It contains the following species:* Colombian Crake, Neocrex colombiana* Paint-billed Crake, Neocrex erythrops...
(2 species) - PardirallusPardirallusPardirallus is a genus of bird in the rail family, Rallidae. It contains three species found in marshland in South and Central America and the West Indies. They are 25–38 cm long and have a long greenish bill and reddish legs...
(3 species) - Eulabeornis - Chestnut RailChestnut RailThe Chestnut Rail is a species of bird in the Rallidae family. The Chestnut Rail is monotypical of its genus.It is found in Australia and Indonesia.Its natural habitat is subtropical or tropical mangrove forests....
- Habroptila - Invisible RailInvisible RailThe Invisible Rail is a flightless species of bird in the family Rallidae , 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...
- Megacrex - New Guinea Flightless RailNew Guinea Flightless RailThe 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...
- Gallicrex - WatercockWatercockThe Watercock Gallicrex cinerea is a waterbird in the rail and crake family Rallidae. It is the only member of the genus Gallicrex....
- PorphyrioPorphyrioPorphyrio is the swamphen genus of birds in the rail family. It includes some smaller species which are usually called "purple gallinules", and which are sometimes separated as genus Porphyrula or united with the gallinules proper in Gallinula. There are two living species of swamphen, the...
- swamphens and purple gallinules (6 living species, 2-5 recently extinct; includes Notornis and Porphyrula) - GallinulaMoorhenMoorhens, sometimes called marsh hens, are medium-sized water birds that are members of the rail family Rallidae. They constitute the genus Gallinula....
- typical gallinules (7-9 living species, 1-3 recently extinct; includes Edithornis and Pareudiastes) - Fulica - coots (c.10 living species, 1 recently extinct)
Additionally, there are many prehistoric rails of extant genera, known only from fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
or subfossil remains, such as the Ibiza Rail
Ibiza Rail
The Ibiza Rail is a new species of rail, described from a late Pleistocene to Holocene cave deposit at Es Pouàs, on the island of Ibiza. Ibiza is in the Pityuses group of the Spanish Balearic Islands in the Mediterranean Sea...
(Rallus eivissensis). These have not been listed here; see the genus accounts and the articles on fossil and Late Quaternary prehistoric birds for these species.
Recently extinct genera
- Genus Nesotrochis - cave-rails (3 species; extinctExtinctionIn biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
prehistoric or later)- Antillean Cave RailAntillean Cave RailThe Antillean Cave Rail , also known as DeBooy's Rail, is an extinct rail species which occurred on Puerto Rico and the United States Virgin Islands. Bone fragments of this species were first unearthed by archaeologist Theodoor de Booy in kitchen midden deposits on the Richmond estate near...
, Nesotrochis debooyi (Puerto Rico and Virgin Islands, West Indies) - may have survived until historic times - Haitian Cave-Rail, Nesotrochis steganinos (Haiti, West Indies) - prehistoric
- Cuban Cave-Rail, Nesotrochis picapicensis (Cuba, West Indies) - prehistoric
- Antillean Cave Rail
- Genus Diaphorapteryx - Hawkins' RailHawkins' RailHawkins' Rail or Giant Chatham Island Rail, Diaphorapteryx hawkinsi, was a flightless extinct bird endemic to the Chatham Islands east of New Zealand. It is known to have existed only on the main islands of Chatham Island and Pitt Island...
(extinct 19th century) - Genus AphanapteryxAphanapteryxAphanapteryx is a small genus of extinct birds of the rail family, endemic to the Mascarenes.The two flightless island species were* Red Rail or Mauritian Red Rail, Aphanapteryx bonasia which became extinct on Mauritius ca 1700...
(2 species; extinct mid-18th century) - Genus Cabalus - Chatham RailChatham RailThe Chatham Rail is an extinct species of bird in the Rallidae family. It was endemic to New Zealand.Cabalus modestus was endemic to Chatham, Mangere and Pitt Islands, New Zealand. It was first discovered on Mangere in 1871, and 26 specimens collected there are known from museum collections. It...
(sometimes included in Gallirallus; extinct c. 1900) - Genus Mundia - Ascension Crake - formerly included in Atlantisia; (late 17th century)
- Genus Aphanocrex - St Helena SwamphenSt Helena SwamphenThe Saint Helena Swamphen was a large flightless rail from Saint Helena. It became extinct in the early 16th century....
(formerly included in Atlantisia; extinct 16th century)
The undescribed Fernando de Noronha Rail, genus and species undetermined, probably survived to historic times.
Late Quaternary prehistoric extinctions
- Genus CapellirallusSnipe-railThe Snipe-rail is an extinct flightless rail endemic to the North Island of New Zealand. The species' name is derived from the Karamu Cave from Hamilton where the holotype was discovered in 1954.-Description:...
- Snipe-rail - Genus Vitirallus - Viti Levu Rail. The holotypeHolotypeA holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of Vitirallus watlingiis in the collection of the Museum of New Zealand Te Papa TongarewaMuseum of New Zealand Te Papa TongarewaThe Museum of New Zealand Te Papa Tongarewa is the national museum and art gallery of New Zealand, located in Wellington. It is branded and commonly known as Te Papa and Our Place; "Te Papa Tongarewa" is broadly translatable as "the place of treasures of this land".The museum's principles...
. - Genus Hovacrex - Hova-gallinule
and see genus accounts
Fossil record
FossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
species of long-extinct prehistoric rails are richly documented from the well-researched formations of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, as well from the less comprehensively studied strata elsewhere:
- Genus Eocrex (Wasatch Early Eocene of Steamboat Springs, USA)
- Genus Palaeorallus (Wasatch Early Eocene of Wyoming, USA)
- Genus Parvirallus (Early - Middle Eocene of England)
- Genus Aletornis (Bridger Middle Eocene of Uinta County, USA) - includes Protogrus
- Genus Fulicaletornis (Bridger Middle Eocene of Henry's Fork, USA)
- Genus Latipons (Middle Eocene of Lee-on-Solent, England)
- Genus Ibidopsis (Hordwell Late Eocene of Hordwell, UK)
- Genus Quercyrallus (Late Eocene -? Late Oligocene of France)
- Genus Belgirallus (Early Oligocene of WC Europe)
- Genus Rallicrex (Corbula Middle/Late Oligocene of Kolzsvár, Romania)
- Rallidae gen. et sp. indet. (Late Oligocene of Billy-Créchy, France)
- Genus Palaeoaramides (Late Oligocene/Early Miocene - Late Miocene of France)
- Genus RhenanorallusRhenanorallusRhenanorallus is a genus of prehistoric rail which existed in Mainz Basin, Germany during the late Oligocene or early Miocene. It was described by Gerald Mayr in 2010, from a humerus. The type species is Rhenanorallus rhenanus....
(Late Oligocene/Early Miocene of Mainz Basin, Germany) - Genus Paraortygometra (Late Oligocene/?Early Miocene -? Middle Miocene of France) - includes Microrallus
- Genus Pararallus (Late Oligocene? - Late Miocene of C Europe) - possibly belongs in Palaeoaramides
- Rallidae gen. et sp. indet. (Bathans Early/Middle Miocene of Otago, New Zealand)
- Rallidae gen. et sp. indet. (Bathans Early/Middle Miocene of Otago, New Zealand)
- Genus Miofulica (Anversian Black Sand Middle Miocene of Antwerp, Belgium)
- Genus Miorallus (Middle Miocene of Sansan, France -? Late Miocene of Rudabánya, Hungary)
- Genus Youngornis (Shanwang Middle Miocene of Linqu, China)
- Rallidae gen. et sp. indet. (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary)
- Rallidae gen. et sp. indet. (Middle Miocene of Grive-Saint-Alban, France)
- Rallidae gen. et sp. indet. (Late Miocene of Lemoyne Quarry, USA)
- Rallidae gen. et sp. indet. UMMP V55013-55014; UMMP V55012/V45750/V45746 (Rexroad Late Pliocene of Saw Rock Canyon, USA)
- Rallidae gen. et sp. indet. UMMP V29080 (Rexroad Late Pliocene of Fox Canyon, USA)
- Genus Creccoides (Blanco Late Pliocene/Early Pleistocene of Crosby County, USA)
- Rallidae gen. et sp. indet. (Bermuda, West Atlantic)
- Rallidae gen. et sp. indet. (formerly Fulica podagricaBarbados RailThe Barbados Rail is a fossil rail species endemic to Barbados with an undetermined taxonomic status. It was formerly described by Pierce Brodkorb in 1965 as Fulica podagrica. However, this classification has been questioned by Storrs Olson when he described Brodkorb's material anew in 1974...
) (Late Pleistocene of Barbados) - Genus Pleistorallus (mid-Pleistocene New Zealand). The holotypeHolotypeA holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of Pleistorallus flemingiis in the collection of the Museum of New Zealand Te Papa TongarewaMuseum of New Zealand Te Papa TongarewaThe Museum of New Zealand Te Papa Tongarewa is the national museum and art gallery of New Zealand, located in Wellington. It is branded and commonly known as Te Papa and Our Place; "Te Papa Tongarewa" is broadly translatable as "the place of treasures of this land".The museum's principles...
.
Doubtfully placed here
These taxa may or may not have been rails:- Genus LudiortyxLudiortyxLudiortyx is a bird genus from the Late Eocene. Its remains have been found in the Montmartre Formation at the Montmartre . A single species is accepted, Ludiortyx hoffmanni....
(Late Eocene) - includes "Tringa" hoffmanni, "Palaeortyx" blanchardi, "P." hoffmanni - Genus Telecrex (Irdin Manha Late Eocene of Chimney Butte, China)
- Genus Amitabha (Bridger middle Eocene of Forbidden City, USA) - phasianid?
- Genus Palaeocrex (Early Oligocene of Trigonias Quarry, USA)
- Genus Rupelrallus (Early Oligocene of Germany)
- Neornithes incerta sedis (Late Oligocene of Riversleigh, Australia)
- Genus Euryonotus (Pleistocene of Argentina)
The presumed scolopacid wader
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
Limosa gypsorum (Montmartre Late Eocene of France) is sometimes considered a rail and then placed in the genus Montirallus.