Common moorhen

Common moorhen
Young adult, WWT London Wetland Centre, Barnes
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Subclass:	Neornithes
Infraclass:	Neognathae
Superorder:	Neoaves
Order:	Gruiformes
Family:	Rallidae
Genus:	Gallinula
Species:	G. chloropus
Binomial name
Gallinula chloropus (Linnaeus, 1758)
Subspecies
About 5, see text
Range of G. chloropus      Breeding range     Year-round range     Wintering range
Synonyms
Fulica chloropus Linnaeus, 1758

The common moorhen (Gallinula chloropus) (also known as the swamp chicken) is a bird species in the family Rallidae. It is distributed across many parts of the Old World.

The common moorhen lives around well-vegetated marshes, ponds, canals and other wetlands. The species is not found in the polar regions or many tropical rainforests. Elsewhere it is likely the most common rail species, except for the Eurasian coot in some regions.

The closely related common gallinule of the New World has been recognized as a separate species by most authorities, starting with the American Ornithologists' Union and the International Ornithological Committee in 2011.

Name

The name mor-hen has been recorded in English since the 13th century. The word moor here is an old sense meaning marsh; the species is not usually found in moorland. An older name, common waterhen, is more descriptive of the bird's habitat.

A "watercock" is not a male "waterhen" but the rail species Gallicrex cinerea, not closely related to the common moorhen. "Water rail" usually refers to Rallus aquaticus, again not closely related.

The scientific name Gallinula chloropus comes from the Latin Gallinula (a small hen or chicken) and the Greek chloropus (khloros χλωρός green or yellow, pous πούς foot).

Description and ecology

Common moorhen feet have no webbing

The moorhen is a distinctive species, with dark plumage apart from the white undertail, yellow legs and a red frontal shield. The young are browner and lack the red shield. The frontal shield of the adult has a rounded top and fairly parallel sides; the tailward margin of the red unfeathered area is a smooth waving line. In the related common gallinule of the Americas, the frontal shield has a fairly straight top and is less wide towards the bill, giving a marked indentation to the back margin of the red area.

The common moorhen gives a wide range of gargling calls and will emit loud hisses when threatened. A midsized to large rail, it can range from 30 to 38 cm (12 to 15 in) in length and span 50 to 62 cm (20 to 24 in) across the wings. The body mass of this species can range from 192 to 500 g (6.8 to 17.6 oz).

Moorhen sighted in Fangu, Corsica (France)

This is a common breeding bird in marsh environments and well-vegetated lakes. Populations in areas where the waters freeze, such as eastern Europe, will migrate to more temperate climes. This species will consume a wide variety of vegetable material and small aquatic creatures. They forage beside or in the water, sometimes walking on lilypads or upending in the water to feed. They are often secretive, but can become tame in some areas. Despite loss of habitat in parts of its range, the common moorhen remains plentiful and widespread.

The birds are territorial during breeding season. The nest is a basket built on the ground in dense vegetation. Laying starts in spring, between mid-March and mid-May in Northern hemisphere temperate regions. About 8 eggs are usually laid per female early in the season; a brood later in the year usually has only 5–8 or fewer eggs. Nests may be re-used by different females. Incubation lasts about three weeks. Both parents incubate and feed the young. These fledge after 40–50 days, become independent usually a few weeks thereafter, and may raise their first brood the next spring. When threatened, the young may cling to the parents' body, after which the adult birds fly away to safety, carrying their offspring with them.

On a global scale – all subspecies taken together – the common moorhen is as abundant as its vernacular name implies. It is therefore considered a species of Least Concern by the IUCN. However, small populations may be prone to extinction. The population of Palau, belonging to the widespread subspecies G. c. orientalis and locally known as debar (a generic term also used for ducks and meaning roughly "waterfowl"), is very rare, and apparently the birds are hunted by locals. Most of the population on the archipelago occurs on Angaur and Peleliu, while the species is probably already gone from Koror. In the Lake Ngardok wetlands of Babeldaob, a few dozen still occur, but the total number of common moorhens on Palau is about in the same region as the Guam population: fewer than 100 adult birds (usually fewer than 50) have been encountered in any survey.

The common moorhen is one of the birds (the other is the Eurasian coot, Fulica atra) from which the cyclocoelid flatworm parasite Cyclocoelum mutabile was first described. The bird is also parasitised by the moorhen flea, Dasypsyllus gallinulae.

Subspecies

Five subspecies are today considered valid; several more have been described that are now considered junior synonyms. Most are not very readily recognizable, as differences are rather subtle and often clinal. Usually, the location of a sighting is the most reliable indication as to subspecies identification, but the migratory tendencies of this species make identifications based on location not completely reliable. In addition to the extant subspecies listed below, an undescribed form from the Early Pleistocene is recorded from Dursunlu in Turkey.

List of subspecies by date of description
Common and trinomial names		Description	Range
Eurasian common moorhen G. c. chloropus (Linnaeus, 1758) Includes correiana and indica.		Wings and back blackish-olive	Ranges from Northwest Europe to North Africa and eastwards to Central Siberia and from the humid regions of the Indian Subcontinent and Southeast Asia eastwards to Japan; also found the Canary, Azores, Madeira, and Cape Verde islands.
Indo-Pacific common moorhen G. c. orientalis (Horsfield, 1821)		Small, with slate grey upperwing coverts and large frontal shield.	Found in the Seychelles, Andaman Islands, and South Malaysia through Indonesia; also found in the Philippines and Palau. The breeding population existing on Yap in Micronesia since the 1980s is probably of this subspecies, but might be of the rare G. c. guami. Population size: Perhaps a few 100s on Palau as of the early 2000s, less than 100 on Yap as of the early 2000s.
African common moorhen G. c. meridionalis (C. L. Brehm, 1831)		Similar to orientalis, but the frontal shield is smaller.	Found in Sub-Saharan Africa and Saint Helena.
Madagascan common moorhen G. c. pyrrhorrhoa (A. Newton, 1861)		Similar to meridionalis, but the undertail coverts are buff.	Found on the islands of Madagascar, Réunion, Mauritius, and the Comoros.
Mariana common moorhen G. c. guami (Hartert, 1917) Called pulattat in Chamorro.		Body plumage is very dark.	Endemic to the Northern Mariana Islands, but see also G. c. orientalis above. Population size: About 300 as of 2001.

Gallery

Eggs, Collection Museum Wiesbaden, Germany

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  Common Moorhen chick having a paddle

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  collecting for nest, Wolvercote, Oxfordshire

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  on nest, Wolvercote, Oxfordshire

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  G. c. chloropus nest with small clutch of eggs at Wilgenhoek, Deerlijk (Belgium)

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  Chick, 1–2 weeks old

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  Moorhen feeding chick some regurgitated food

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  Immature G. c. chloropus, 3–4 months old, in Parc de Bercy, Paris (France)

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  Juvenile, Strumpshaw Fen, Norfolk

External links

• (Common) Moorhen species text in The Atlas of Southern African Birds
• Common moorhen videos, photos, and sounds at the Internet Bird Collection
• Common Gallinule Species Account – Cornell Lab of Ornithology
• Common Moorhen Information - Gallinula chloropus - USGS Patuxent Bird Identification InfoCenter
• Madeira Birds – Moorhen breeding in Madeira Island
• Ageing and sexing (PDF; 5.7 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze
• BirdLife species factsheet for Gallinula chloropus
• Common moorhen photo gallery at VIREO (Drexel University)
• Audio recordings of Common moorhen on Xeno-canto.

• Common moorhen media at ARKive Retrieved 25 February 2013.