Moorhens, sometimes called
marsh hens, are medium-sized water birds which are members of the rail
familyIn 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...
RallidaeThe 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...
. They constitute the
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
Gallinula.
They are close relatives of
cootCoots are medium-sized water birds which 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, and because of their apparently nervous behavior (frequently twitching tail, neck and grinding their backs) are sometimes called "skitty coots". Often, they are referred to as
(black) gallinules.
A few
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
from the
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
n region, sometimes separated in
Tribonyx, are called
native-hens.
Tribonyx is better considered a
subgenusIn biology, a subgenus is a taxonomic rank directly below genus. See rank and rank .In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic and specific name: e.g...
however as the differences are not very striking and mainly plesiomorphic. The native-hens differ visually by shorter, thicker and stubbier toes and bills, and longer tails that lack the white signal pattern of typical moorhens.
Description
These rails are mostly brown and black with some white markings in
plumageFeathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates. They are among the outstanding characteristics that distinguish the extant Aves from other living groups....
colour. Unlike many of the rails they are usually easy to see, feeding in open water margins rather than hidden in reedbeds.
They have short rounded wings and are weak fliers, although usually capable of covering long distances. The
Common MoorhenThe Common Moorhen is a bird in the Rail family with an almost worldwide distribution. It is often called the "Common Waterhen", especially in the British Isles, and this is a more descriptive name because the bird lives around well-vegetated marshes, ponds, canals, etc., and is usually not found...
in particular
migratesBird 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. These however are usually irregular or in only one direction and are termed variously as nomadism, invasions,...
up to 2,000 km from some of its breeding areas in the colder parts of
SiberiaSiberia , is the vast region constituting almost all of Northern Asia and for the most part currently serving as the massive central and eastern portion of the Russian Federation, having served in the same capacity previously for the USSR from its beginning, and the Russian Empire beginning in the...
. Those that migrate do so at night. The
Gough Island MoorhenThe Gough Island Moorhen, Gallinula comeri, is a medium-sized, almost flightless bird that is similar to the Common Moorhen , but is smaller, stockier, and has shorter wings. The bird has a distinctive bill that is reddish with a yellow tip. Its first account was written by the polar explorer...
on the other hand is considered almost flightless - it can only flutter some meters. As common in rails, there has been a marked tedency to
evolveEvolve may refer to:*Evolve, as in Evolution.*Evolve on The History Channel*Evolve Festival, an annual music and cultural festival held in Nova Scotia, Canada.*Evolve Cars, an after-market manufacturer of sport-parts for Volvo cars....
flightlessnessFlightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim, and are thought to have evolved from their flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguins...
in island populations.
Moorhens can walk very well on strong legs, and have long toes that are well adapted to soft uneven surfaces.
These birds are omnivorous taking plant material, small rodents, amphibians and
eggIn most birds and reptiles, an egg is the zygote, resulting from fertilization of the ovum. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo. When the embryo is adequately developed it breaks out of the egg in the...
s. They are aggressively territorial during the breeding season, but are otherwise often found in sizeable flocks on the shallow vegetated lakes they prefer.
Systematics and evolution
Living and recently extinct
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
of
Gallinula are:
- Samoan Moorhen, Gallinula pacifica – sometimes placed in Pareudiastes, extinct (1907)?
- Makira Moorhen
The Makira Moorhen is a species of bird in the Rallidae family.It is endemic to Solomon Islands.Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montanes....
, Gallinula silvestris – sometimes placed in Pareudiastes or Edithornis, extinct (mid-20th century)?
- Tristan Moorhen
The Tristan Moorhen is an extinct flightless rail from the South Atlantic island of Tristan da Cunha. It was physically similar to the Gough Island Moorhen of Gough Island, located 395 miles to the southeast....
, Gallinula nesiotis – extinct (late 19th century)
- Gough Island Moorhen
The Gough Island Moorhen, Gallinula comeri, is a medium-sized, almost flightless bird that is similar to the Common Moorhen , but is smaller, stockier, and has shorter wings. The bird has a distinctive bill that is reddish with a yellow tip. Its first account was written by the polar explorer...
, Gallinula comeri
- Common Moorhen
The Common Moorhen is a bird in the Rail family with an almost worldwide distribution. It is often called the "Common Waterhen", especially in the British Isles, and this is a more descriptive name because the bird lives around well-vegetated marshes, ponds, canals, etc., and is usually not found...
, Gallinula chloropus
- Dusky Moorhen
The Dusky Moorhen is a bird in the rail family. It occurs in Australia, New Guinea and Indonesia.The New Guinea birds are smaller, at 25-32 cm in length, than the Australian race...
, Gallinula tenebrosa
- Lesser Moorhen
The Lesser Moorhen is a species of bird in the Rallidae family.It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial Guinea, Ethiopia, Gabon, Gambia, Ghana,...
, Gallinula angulata
- Spot-flanked Gallinule
The Spot-flanked Gallinule is a species of bird in the Rallidae family.It is found in Argentina, Bolivia, Brazil, Chile, Colombia, Paraguay, Peru, and Uruguay.Its natural habitats are swamps and freshwater lakes.-References:...
, Gallinula melanops
- Black-tailed Native-hen
The Black-tailed Native-hen, , is a rail native to Australia and New Zealand.-Description:The Black-tailed Native-hen is a large dark bird, reaching about 38cm in length and weighing around 400g. This species possesses an erect tail and is endowed almost entirely in brownish-grey and green feathers...
, Gallinula ventralis
- Tasmanian Native-hen
The Tasmanian Native-hen is a flightless rail, one of twelve species of birds endemic to the Australian island of Tasmania...
, Gallinula mortierii
Other moorhens have been described from older remains. Apart from the 1-3 extinctions in more recent times, another 1-4 species have gone extinct as a consequence of early human settlement: Hodgen's Waterhen (
Gallinula hodgenorum) of
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...
- which belongs in
subgenusIn biology, a subgenus is a taxonomic rank directly below genus. See rank and rank .In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic and specific name: e.g...
Tribonyx -, and a species close to the Samoan Moorhen from
BukaBuka can refer to:* Buka, Papua New Guinea, the war capital of Bougainville Province.* Buka Island is the second largest island in the Papua New Guinean province of Bougainville.* Buka Entertainment, a computer game publisher...
,
Solomon IslandsThe Solomon Islands is a country in Melanesia, east of Papua New Guinea, consisting of nearly one thousand islands. Together they cover a land mass of 28,400 square kilometres . The capital is Honiara, located on the island of Guadalcanal.The Solomon Islands are believed to have been...
, which is almost certainly distinct from the
Makira MoorhenThe Makira Moorhen is a species of bird in the Rallidae family.It is endemic to Solomon Islands.Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montanes....
as the latter cannot fly. The undescribed Viti Levu Gallinule of
FijiFiji , officially the Republic of the Fiji Islands , is an island nation in the South Pacific Ocean east of Vanuatu, west of Tonga and south of Tuvalu. The country comprises an archipelago of about 322 islands, of which 106 are permanently inhabited, and 522 islets...
would either be separated in
Pareudiastes if that genus is considered valid, or may be a completely new genus. Similarly, the undescribed Mangaia "swamphen" which is currently tentatively assigned to
PorphyrioPorphyrio 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...
may belong to
Gallinula/
Pareudiastes.
Evolution
Still older
fossilFossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record...
s document the genus since the Late Oligocene onwards. The genus seems to have originated in the
Southern HemisphereThe Southern Hemisphere is the half of a planet that is south of the equator—the word hemisphere literally means 'half ball'...
, in the general region of
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
. By the
PlioceneThe Pliocene epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present....
, it was probably distributed worldwide:
- Gallinula disneyi (Late Oligocene - Early Miocene of Riversleigh, Australia)
- Gallinula sp. (Early Pliocene of Hungary and Germany)
- Gallinula kansarum (Late Pliocene of Kansas, USA)
- Gallinula balcanica (Late Pliocene of Varshets, Bulgaria).
- Gallinula gigantea (Early Pleistocene of Czechia and Israel)
Even among non-Passeriformes, this genus has a long documented existence. Consequently some unassigned fragmentary rail fossils might also be from moor- or native-hens. For example, specimen
QMThe Queensland Museum is a museum at South Bank in Brisbane, Queensland, Australia. The museum is funded by the State Government of Queensland.Two affiliate museums are in regional centres Toowoomba and Townsville.-History:...
F30696, a left distal
tibiotarsusThe tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia.A similar structure also occurred in the Mesozoic Heterodontosauridae...
piece from the Oligo-Miocene boundary at
RiversleighRiversleigh, in North West Queensland, is Australia's most famous fossil site. The 100 km² area has fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age...
, is similar to but than and differs in details from
G. disneyi. It cannot be said if this bird - if it was a distinct species - was flightless; from its size alone it might have been an ancestor of
G. mortierii (see also below).
In addition to paleosubspecies of
Gallinula chloropus, the doubtfully distinct Late Pliocene to Pleistocene
Gallinula mortierii reperta was described, referring to the population of the
Tasmanian Native-henThe Tasmanian Native-hen is a flightless rail, one of twelve species of birds endemic to the Australian island of Tasmania...
that once inhabited mainland Australia and became extinct at the end of the last ice age. It may be that apart from
climate changeClimate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average...
it was driven to extinction by the introduction of the
dingoThe Dingo is a domestic dog which has reverted to a wild state for thousands of years and today lives largely independent from humans in the majority of its distribution....
, which as opposed to the
marsupialMarsupials are an infraclass of mammals, characterized by a distinctive pouch , in which females carry their young through early infancy.- History :...
predators hunted during the day, but this would require a survival of mainland
Gallinula mortierii to as late as about 1500 BC
G. disneyi was yet another flightless native-hen - indicative of that group's rather basal position among moorhens -, and its time and place of occurrence suggest it as an ancestor of
G. mortierii (reperta), from which it differed mostly in its much smaller size. However, some limb bone proportions are also strikingly different, and in any case such a scenario would require a flightless bird to change but little during some 20 million years in an environment rich in predators. As the fossils of
G. disneyi as well as the rich recent and
subfossilSubfossil refers to remains whose fossilization process is not complete, either for lack of time or because the condition in which they were buried were not optimal for fossilization....
material of
G. mortierii shows no evidence of such a change at all,
G. disneyi more probably represents a case of
parallel evolutionParallel evolution is the development of a similar trait in different not closely related species , but descending from the same ancestor.-Parallel vs...
at an earlier date.
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