South Sea Moorhen
| South Sea Moorhen | ||||||||||||
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South Sea Moorhen |
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| Scientific name | ||||||||||||
| Zapornia tabuensis | ||||||||||||
| ( Linnaeus , 1766) |
The South Sea Crake ( Zapornia tabuensis , Syn. : Porzana tabuensis ) is a type of Rails , belonging to the genus today Zapornia is counted. It is a small, dark, and short-tailed rallen species that can be found from the Philippines to Australia and New Zealand. Due to its size and dark plumage, it is not to be confused with any other rail species in its range.
The population of the South Sea Moorhen is given as least concern . Several subspecies are distinguished.
Appearance
The South Sea Moorhen reaches a body length of 17 to 20 centimeters, of which 4.4 to 5.7 centimeters are on the tail. The wing measures 8.2 to 9.2 centimeters. The beak length is 1.6 to 2.2 centimeters. The males weigh an average of 45.5 grams, the females are slightly lighter at 40 grams. There is no gender dimorphism .
Adult birds
The head and neck are slate gray with a whitish spot on the chin, which in some individuals extends in a narrow strip to the throat. The mantle, the back and the wing covers are dark reddish brown. The tail is black-brown. The underside of the body is slate gray with white transverse bands on the inside of the wings. The beak is black, the iris and the orbital ring are red. The feet and legs are salmon red.
Fledglings
Fledglings resemble the adult birds, but are generally a little paler and brown. The white spot on their chin and throat is a little more pronounced. Some individuals also have a diffuse little white stripe above the eyes. The flanks are brown, on the middle of the chest and the belly they are still whitish. The iris is initially brown-orange before it takes on the red of the adult birds. The legs and feet are dark olive-brown to brown-gray.
Distribution area and habitat
The South Sea Moorhen occurs from the Philippines via Indonesia, the Marquesas and New Guinea to Australia, Tasmania, New Zealand and islands of the southwestern Pacific. The Norfolk Islands , the Kermadec Islands and also for the Chatham Islands there is evidence of this species. In Australia it is a common species that occurs disjointly on the Australian mainland . It is less common in New Zealand, but it is widespread. The main area of distribution is the North Island, but it also occurs on the South Island. The migration and migration of this type of rail has not yet been conclusively investigated. However, ringing data from New Zealand indicate a high degree of locality.
The habitat is permanent or short-term wetlands. They usually have an extensive vegetation zone with reeds, blessings or similar plants. The bank zones are populated by rivers, lagoons, lakes and salt marshes. On islands it is occasionally found in less humid habitats.
Way of life
The South Sea Moorhen lives solitary, in pairs or in small, loose groups in the dense vegetation of wetlands. Basically, it is a secretly living species that seldom leaves the protective vegetation zone while searching for food and stays in more open terrain. While foraging for food, the species also stands in the water. The South Sea Moorhen can also swim and dive. It rarely flies up and then usually does not fly far. The flight seems strained and fluttering, the feet droop during the flight. The South Sea Moorhen is predominantly crepuscular, but also occasionally looks for food during the day. If it feels disturbed, it looks for denser vegetation and remains there motionless.
The diet consists of seeds, fruits, shoots of grass and aquatic plants. It also eats insects and their larvae, molluscs and crustaceans, spiders and also goes on carrion. The leaf layer lying on the ground is cooked through by it and the leaves are turned over with a sideways movement of the beak.
Reproduction
The South Sea Moorhen is monogamous and may have a relationship that lasts for several breeding seasons. Before the start of the breeding season, this moorhen calls more intensely, which may be related to the pair bond and the occupation of the breeding area. The breeding ground is vigorously defended by the couple. In regions where the South Sea Moorhen find very good living conditions, the breeding grounds can also be very small. In some cases they are only five to twelve square meters. Two broods are usually raised in each breeding season.
The breeding season falls from August to early December. The nest stands in the bank vegetation made of dry grass and reed stalks. The clutch usually consists of three to four eggs. The second clutch of a breeding season usually has the larger number of eggs. The laying interval between the individual eggs is 24 hours. If the clutch is lost, South Sea Moorhens are able to start a replacement clutch about seven days later.
Both parent birds breed. There are very different figures for the duration of the breeding season. 14 to 16 days, 16 to 18 days and 20 to 22 days are mentioned. The newly hatched chicks stay in the nest for between 24 and 48 hours. They are first led by both parent birds. The chicks, which initially have black down plumage, can swim within two days. When alarmed, they seek shelter in the vegetation. The parent birds try to seduce predators by simulating injuries.
Systematics
The South Sea Moorhen is still often assigned to the genus of the Moorhen ( Porzana ). In a molecular biological study by Slikas et al. from 2002, however, several clades were visible within the moorhens of the genus Porzana . This knowledge was followed by a division of this genus and corresponding nomenclature measures. These have not yet been finally confirmed, but have since been included in well-known monographs and lists. The South Sea Moorhen was assigned to the genus Zapornia
literature
- Bruce M. Beehler, Thane K. Pratt: Birds of New Guinea; Distribution, Taxonomy, and Systematics . Princeton University Press, Princeton 2016, ISBN 978-0-691-16424-3 .
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 2, Raptors to Lapwings, Oxford University Press, Oxford 1993, ISBN 0-19-553069-1 .
Web links
Individual evidence
- ↑ a b c d Handbook of the Birds of the World zum Südsee-Moorhuhn accessed on May 31, 2017.
- ↑ a b c Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 559.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 565.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 560.
- ↑ a b Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 561.
- ↑ a b c Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 562.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 563.
- ↑ a b c Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 564.
- ↑ Beth Slikas, Storrs L. Olson & Robert C. Fleischer: Rapid, independent evolution of flightlessness in four species of Pacific Island rails (Rallidae): an analysis based on mitochondrial sequence data. Journal of Avian Biology, 33, 1, pp. 5-14, 2002
- ^ EC Dickinson & JV Remsen, Jr. (Eds.): The Howard and Moore Complete Checklist of the Birds of the World. 4th edition, Vol. 1. Non-passerines. Aves Press, 2013, pp. 149-161 ISBN 978-0-9568611-0-8