The dusky moorhen (Gallinula tenebrosa) is a bird species in the rail family and is one of the eight extant species in the moorhen genus. It occurs in Australia, New Guinea, Borneo and Indonesia. It is often confused with the purple swamphen and the Eurasian coot due to similar appearance and overlapping distributions. They often live alongside birds in the same genus, such as the Tasmanian nativehen and the common moorhen.
Taxonomy
John Gould described the dusky moorhen in 1846 from a skin collected along the Murray River in South Australia. Its species name is derived from the Latin tenebrosa "dark". Charles Lucien Bonaparte described Gallinula haematopus in 1856, but this is now a nomen nudum. Gregory Mathews described two subspecies that have been synonymized—magnirostris from Western Australia and subfrontata from New South Wales. than the Australian race . Adult males generally weigh on average around 570 grams and adult females 493 grams.
Diet
The dusky moorhen feeds both on land and in water. Its diet consists of seeds, the tips of shrubs and grasses, algae, fruits, molluscs, and other invertebrates. It will also consume carrion, bread and droppings from birds including gulls and ducks. The chicks are fed mostly on annelid worms and molluscs, with plant matter gradually being given in increasing proportions by the parents as the young mature.
Voice
The territorial call is a loud kurk or krik, which may be repeated or run together, sounding like kurruk-uk. This call is taken up by birds in surrounding territories and can be heard from over two kilometres away. The birds also make a series of short, sharp squawks and squeaks as alarm calls. Swimming and preening birds may make a series of short, stacatto, widely spaced noises.
Both sexes make a soft mewing noise, or a soft kook noise before and during courtship. Adults may make a quiet hissing noise when their eggs are disturbed. Chicks under the age of three months make a repeated shrill piping noise when begging, when an adult approaches with food, and when they are separated from adults. Adults also make short clicking noises when separated from chicks, and the young give a series of descending whistles in response. It is also found in parts of Tasmania and South Australia, but are uncommon. Included in their natural distribution range are wildlife parks such as Currumbin Wildlife Sanctuary and the Brisbane Botanic Gardens.
The dusky moorhen is found in wetland habitats, with a preference for freshwater marshes and swamps, and are rarely found far from these areas except when foraging in nearby vegetation. They require open water, usually with some cover such as grass, reeds, and other vegetation. In south-east Queensland, they are more likely to be found in areas with taller vegetation, more attached aquatic vegetation, and a larger number of purple swamphens, indicating that the availability of food and other resources affects their numbers and distribution in wetlands. They usually live in low-lying areas, although a pair have been found as high up as 1,580 metres in New Guinea, likely having been separated from their flock. This species builds a bulky nest of reeds or grasses at the water's edge or a few centimetres above the water, often at the base of a Melaleuca and lays a clutch of 5–11 matte whitish eggs that are covered with red-brown dots and splotches. Tapered oval in shape, they measure 53 mm long by 36 mm wide each and have more prominent markings at the larger end.