Madagascar pension
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Madagascar pension |
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| Systematics | ||||||||||||
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| Anas melleri | ||||||||||||
| Sclater , 1865 |
The Madagascar duck ( Anas melleri ) is a duck bird that is counted among the swimming ducks. Its natural range is Madagascar. Like the Madagascar bog duck, it is one of the most endangered ducks in the world. The specific epithet honors the naturalist Charles James Meller , who collected the type material for Philip Lutley Sclater .
Appearance
The Madagascar duck is a very large duck. It reaches a body length of 65 centimeters. Their body plumage appears monotonously brown from a distance and is reminiscent of the female of the mallard . However, Madagascar peoples can be distinguished by their larger and grayer beak. In Madagascar pens, the head, neck and body feathers also have narrow dark centers and broad brown edges, so that thin dotted lines are created. In the case of the mallard, on the other hand, the face and front neck are almost monochrome and clearly set off from the trunk. In flight, the light under wing coverts stand out clearly from the darker body plumage.
Madagascarents have no gender dimorphism and no seasonal dimorphism. The males are slightly larger than the females and due to their slightly larger skull, their beak looks longer than that of the females. The wing mirror is green and has a white border. In the male, the two middle tail feathers are black at the end. The male also has slightly longer feathers on the flanks. Legs and feet are orange-brown. The eyes are dark brown. Young ducks are similar to adult birds. With them, however, the feather hems are a little more pronounced, so that they appear slightly more contrasting. The chicks resemble those of the mallard. However, the facial drawing is a little different. The dark ear patches are crescent-shaped and extended over the sides of the neck. The elongated beak is noticeable very quickly in growing chicks. The moulting pattern of the Madagascar duck has not yet been fully observed. After the breeding season, however, there is a complete change of plumage and Madagascar ducks are flightless for about a month. The prenuptial moult probably lasts for several months.
The voice of the Madagascar duck resembles that of the mallard. The females quack slightly higher than the females of the mallards and the males' räb goes over three tones.
Distribution and existence
The Madagascar duck is an endemic species of duck from Madagascar. It was introduced in Mauritius around 1850. Presumably, however, Madagascarents are repeatedly drifting to this island by storms.
Since the central highlands of Madagascar were largely deforested, the distribution area of the Madagascar Duck has been limited to the eastern half of the island. Its altitude distribution extends up to 2,000 meters and it may occur at even higher altitudes. It occurs among other things on the two isolated massifs Andringitra and Kalambatritra. A greater concentration of Madagascar ducks can be found at Lac Alaotra , which is located in a large wetland area that is mainly used for rice cultivation. Flocks of non-breeding Madagascar pods can also be found at this lake.
The species is threatened with extinction in Mauritius, where around 20 pairs were breeding in 1970. It will only be able to survive there as a wild population if its population is supplemented by released Madagascar pigs. Overall, the Madagascar duck population is estimated at 2,000 to 5,000 ducks worldwide. The population is declining overall. The causes of the population decline are hunting, habitat loss and increasing environmental pollution in Madagascar. It is thought possible that Madagascarents will no longer colonize some regions of Madagascar after large fish species have been introduced there.
Habitat and food
The Madagascarente prefers freshwater lakes, rivers and wetlands in predominantly forested areas. Slow flowing rivers are their preferred habitat. She often looks for food during the night. Large swarms can form when searching for food. At Lac Alaotra you can often see them together with the brown ibis .
They find their food by rooting or taking in from the surface of the water. Occasionally they also look for food on the banks. The food composition of wild Madagascar ducks has not yet been adequately investigated. Vegetable food, however, plays a major role. Among other things, it eats the components of water lilies. It also eats invertebrates such as shellfish.
Reproduction
During the breeding season, mallards are territorial. Their clearly defined territory is vigorously defended. Sections of the river are occupied as breeding grounds. Conflicts with other Madagascar peoples predominantly occur at the territorial borders. The male stays in the territory while the female breeds. Unlike many species of duck, there is no swarming of drakes. Mating with other females is rare. The male even prefers to attack the females when another Madagascar pair invades the territory.
The breeding season falls from July to April. Reproduction is likely triggered by rainfall. The nest is built on the ground. The eggs are oval with a shiny surface. The shell color is matt white. The full clutch comprises an average of 8.15 eggs (range 5 to 13 eggs). The female breeds alone. The breeding season is 26 to 28 days. In the case of Madagascarents kept in human care, the chicks fledged in the 11th week of life.
Keeping in human care
Because of their close resemblance to the mallard, Madagascarents do not play a major role in keeping them. The first owner was the London Zoo in 1894. The male kept there mated with a mallard and successfully raised offspring. The Berlin zoo first kept the species in 1930 and was able to breed with it between 1935 and 1939.
Serious breeding efforts began in 1977 through the British Wildfowl Trust and the Jersey Zoo . The Jersey Wildlife Preservation Trust has set itself the goal of conserving this endangered species of duck and has coordinated a breeding program for this species since 1993. The goal is to build a reserve population outside of Madagascar. The zoos involved in this conservation program included the Cologne Zoo , which received two pairs and successfully bred them for the first time in 1998. Madagascar ducks must always be kept in aviaries, otherwise hybridization with mallards is very likely.
supporting documents
Individual evidence
literature
- Janet Kear (Ed.): Ducks, Geese and Swans. Oxford University Press, 2005, ISBN 0198546459 .
- Hartmut Kolbe: The world's ducks. Ulmer Verlag 1999, ISBN 3-8001-7442-1 .
Web links
- Anas melleri inthe IUCN Red List of Threatened Species 2012.2. Listed by: BirdLife International, 2012. Retrieved January 3, 2013.