Lesser White-fronted Goose
Zwerggans
The dwarf goose ( Anser erythropus ), also called Zwergblässgans, is a species of the genus of the field geese ( Anser ) of the family Anatidae ( Anatidae ). It is the rarest species of goose of Europe. The species was first described in 1758 by Carl Linnaeus in his work Systema Naturae. Your breeding area includes the Waldtrundra Eurasia, partly also the northern forest zone and the south of the shrub tundra. During the winter months, they can also be observed in Western Europe. Wintering areas are also found in front and Asia Minor, south of the Caspian Sea, in the Nilebene, in southern Japan, Korea and Southeast China.
Features
The Zwerggans reach a body length of 53-66 inches. It has a wingspan of 120-135 cm and weighs 4.1 to 2.2 kg.
The Zwerggans similar in habit and coloration of the European white-fronted goose, but is smaller and darker. The end pallor extends further upward than in the white-fronted goose and ends between the eyes. From the white-fronted goose, it differs also by the bright yellow eye ring, the already developing young birds. When the young birds he appears for the first time after the youth Mauser in November of the first year of life. In the youth of this dress is dyed green. The Zwerggans is also on the ventral side less striated than the European white-fronted goose and has longer wing tips that dominate the tail of the standing goose a little. The head looks rounder than the gray goose and the beak delicate. In flight it is easy to be confused with the much more common and less protected European white-fronted goose, which has probably led to a significant threat to the existence of their extreme.
The Dunenküken have a great resemblance to those of the white-fronted goose. However, they are somewhat darker on the body surface. As with the Dunenküken this type Zwerggans Chick on the body top and brown on the underparts whitish. Face and neck cream. From bill to eye runs a dark reins. The forehead is reddish brown. At the time of Schlupes the beak is dark olive gray with a pink or cream-colored nail. Legs and feet are olive-gray; The webs are compared to something darker. The beak is colored with increasing age in a pink around. Legs, feet and webbed feet are then yellowish -orange. The iris is dark brown. Striking is the eye-ring, which is light gray in Dunenküken and later umfärbt yellowish.
The Zwerggans has more than a dozen different vocalizations. The voice is much higher than that of the white-fronted goose. The calls often have a sharp shrill and barking than this species of goose.
Dissemination
The distribution area ranged once from the northern parts of Scandinavia over the Urals to Siberia to far. Over the past 25 years she has disappeared from large parts of their breeding grounds. In Scandinavia, there are only a few dozen breeding pairs today. The reintroduction captive -reared geese could not stop the downward trend. Since, in the meantime, the illegal or erroneous hunting was identified in traditional wintering areas in the Balkans as one of the main causes of the stock slump, there is now a project, young feral dwarf geese by ultralights new migration routes to safe wintering areas on the Lower Rhine, for example, a nature reserve Bislicher island to teach.
Way of life
The dwarf goose is a migratory bird that is usually developed south in winter. When she is on her train, they form the characteristic V-formation, often in combination with other species of geese, which can lead to of accidental firing. The migration routes of Zwerggans are not genetically fixed, but are handed down. In addition to the train in the winter quarters, there is a so-called Mauserzug the non-breeding animals at certain moulting places. The departure from the breeding and moulting grounds occurs in the second half of August and early September.
Your search for food geese exclusively in the country. Geese live mainly by short grasses and herbs. For nutrition is important that the areas where geese find food, are covered low, so as to satisfy their need for security, but also because they can feed only on short grass and herbs. For this, natural grazing systems with large grazers ( Megaherbivoren ) are ideal.
Reproduction
The Zwerggans is a breeding bird of higher layers. It breeds preferably in swamp and marshland. Their nest is found in thickets or hills that are free of snow. In years when snowmelt begins very late, she broods occasionally at lower altitudes. Usually show geese a great partner loyalty, however, they re- mate at loss of a partner.
The breeding season begins in late May to early June. It is raised only a clutch per year. The nest is a shallow depression, which are designed with plants, moss, feathers and down. The down used are brownish-gray with a lighter center. The nest usually has five to seven eggs. They are oblong, elliptic to oval and creamy white in color. It breeds only the female parent bird. Breeding begins after the filing of the last ice of the nest. Incubation period is 25-28 days. The Dunenküken are precocial. They are cared for by both parents birds and stay with them during the first winter. After hatching, the chicks, the geese Schwaren together in larger flocks, where they go through their moult. In case of danger, they often flee constantly and do not fly on. You reach for a goose unusually high speed at the bottom. The Mauser swing of the parents is such that they again are a little later than the young animals capable of flight, which facilitates the slow learning more difficult maneuvers of the young animals who follow their parents. Mostly, the young stay until the next breeding with the parent animals and are also often found in these later. Geese can be individually identified by the reputation mainly.
Stock development
Until the early 1950s, the total population consisted of several thousand animals. This was followed in all areas to a dramatic population decline, so that the Zwergblässgans must be considered extremely endangered today. The population in Lapland is only 60 to 90 couples in Hungary overwinter before 1950, more than 100,000 breeding pairs, after 1980 there were only 3,600. Causes of stock decline is excessive hunting in Russia, Kazakhstan and various countries of Eastern and South-Eastern Europe as the Red-breasted Goose. The problem is their great similarity to the much more numerous occurring and intensively hunted white-fronted goose.
The Zwerggans as a globally endangered species of the German Federal Species Protection Ordinance; for animals reared in captivity an exemption from the prohibition of marketing is required.