The common moorhen (Gallinula chloropus), also known as the waterhen or swamp chicken, is a bird species in the rail 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.
The moorhen is a distinctive species, with predominantly black and brown plumage, with the exception of a white under-tail, white streaks on the flanks, yellow legs and a red frontal shield. The bill is red with a yellow tip. 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 (Gallinula galeata) 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.
Habitat includes Wetlands (inland): Permanent Rivers/Streams/Creeks (includes waterfalls), Shrub Dominated Wetlands,
Bogs, Marshes, Swamps, Fens, Peatlands, Permanent Freshwater Lakes (over 8ha), Seasonal/Intermittent Freshwater Lakes (over 8ha), Permanent Freshwater Marshes/Pools (under 8ha), Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha), Permanent Inland Deltas, Permanent Saline, Brackish or alka line Marshes/Pools; Marine Coastal/Supratidal: Coastal Brackish/Saline Lagoons/Marine Lakes, Coastal Freshwater Lakes; Artificial/Aquatic and Marine: Water Storage Areas (over 8ha), Ponds (below 8ha), Irrigated Land (includes irrigation channels), Canals and Drainage Channels, Ditches.
