Mirror geese
| Mirror geese | ||||||||||||
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Magellangans , male |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Chloephaga | ||||||||||||
| Eyton , 1838 |
The mirror geese ( Chloephaga ) are a genus of duck birds . They belong in the subfamily of demi-geese to the tribe Tadornini or "real" demi-geese, which also include the kasarkas , the Egyptian goose , the Orinocogans and the blue-winged goose .
Mirror geese have the typical geese-like habitus of demi-geese. However, several features also indicate a close relationship to the actual ducks . The range of the mirror geese is the South American continent up to the Falkland Islands . The stock situation of the mirror geese is very different. Some species show declines in the population numbers affected and are partially classified as potentially endangered by the IUCN . Other species are not considered endangered. Their food is mainly grass, herbs, seeds and seeds. The Andean Goose eats a very large part of marsh plants such as milfoil and Nostoc , the kelp goose feeds mainly on kelp .
Appearance
Apart from the sea kelp goose, the species of the mirror geese are long-legged ducks. The legs are set relatively far back on the body. The posture is very upright. The kelp goose, which lives on steep and rocky coasts and feeds mainly on brown algae in the kelp forests , is short-legged. It has sharp claws on its feet that allow it to move safely on slippery rocks and find its food. Even the downy chicks of this species have these sharp claws.
With a body length between 45 and 50 centimeters, the red-headed goose is the smallest species among the mirror geese. The largest species is the Andean goose , which can be up to 80 centimeters long and weighs up to 3.6 kilograms. Magellangans, which can reach a maximum size of 65 centimeters and weigh 3.1 kilograms, are only slightly lighter.
Two species show pronounced sexual dimorphism. In the kelp goose and the magellan goose, the basic color of the female is black-brown or bright clay. The males, however, have predominantly white plumage. The kelp goose is even the only species among wild ducks in which the male has pure white plumage. In the other three species - gray-headed goose , red-headed goose and Andean goose - the plumage cannot be used to determine the sex. The females are just a little smaller and lighter. Strong red-brown, clay or cinnamon-colored plumage colorations occur in several species. In the adult female Magellangan, the breast, head and neck are colored. In the red-headed goose this color occurs in the head color and in the gray-headed goose on the chest and front back. There are also black and white plumage bands in several species. The males of the Magellangans have this on the back and, in one subspecies, also on the stomach. In the female Magellança, this black and white banding is visible on the flanks of the breast and stomach. The female kelp goose has these on the front neck, belly and flanks. In the gray-headed goose and the red-headed goose, this black and white banding can be seen particularly well on the flanks. The leg and foot color is inconsistent. Males of the Magellangan have dark gray legs and feet while the females are yellow-orange. This color is present in the other species regardless of gender. With the Andean goose, however, the color is a bit more intense red. All species have a relatively short beak. The beak color ranges from flesh-colored pink to dark gray.
The moulting pattern of some species of mirror geese has not yet been adequately investigated. Basically, the moulting of the swinging feathers takes place during the breeding season and the mirror geese are then not able to fly for some time.
Downy chicks of the mirror geese have a white basic color. Headstock, neck hem, back and sides are black-brown. The color distribution is species-specific, but very similar overall. The downy chicks of the red-headed goose cannot be distinguished from those of the gray-headed goose on the basis of their downy dress.
Distribution area and habitat
Mirror geese are limited in their distribution to the South American continent and to the offshore islands. The Falkland Islands are an important distribution area for some of the mirror goose species. The Andean goose is a high mountain bird that breeds in the valleys of the Andes from an altitude of 3,000 meters and occurs up to 5,000 meters above sea level. The Magellan Goose and the Gray-headed Goose are breeding birds of the southwestern tip of the South American continent and the Falkland Islands. The range of the kelp goose is also the southern tip of South America and the Falkland Island. However, the species is closely tied to the coast. The red-headed goose, on the other hand, lives in the southeastern part of South America and is also found on the Falkland Islands.
Andean goose, magellan goose and red-headed goose inhabit open grass areas. The habitat of the gray-headed goose are river and stream valleys, wooded moors and forest swamps. The kelp goose, on the other hand, only lives on the rocky coast and is rarely found on open pastures.
Reproduction
Mirror geese are extremely aggressive birds during the breeding season and occasionally defend their breeding territory energetically against non-geese. The gray-headed goose attacks territorial intruders, for example with threatening gestures reminiscent of geese. She runs towards the intruder with her head bowed and flaps her wings violently. After a successful expulsion, it shows a shout of triumph , as is characteristic of geese.
The female breeds alone. The incubation period varies slightly depending on the species, but is around 30 days.
Man and mirror geese
Human impact on populations
Several species of mirror geese are declining in their numbers because humans have changed their habitat and sometimes they are still being hunted heavily. Magellan goose, gray-headed goose and red-headed goose have been and are viewed by humans as food competitors to domestic animals. Shooting premiums were paid for all three species . The red headed goose is now under protection on the Falkland Islands after having been hunted intensively for a long time. On the Falkland Islands their population is now stable and these islands are now their main distribution area. On the South American mainland, however, it has largely disappeared. The suspension of the Argentine battle fox , which was naturalized in Tierra del Fuego in the 1950s to fight the rabbit plague there, also contributed to this. The population in Tierra del Fuego is now estimated to be less than 500 individuals and is continuing to decline.
The Andean Goose and the Kelp Goose use habitats that are largely untouched by humans. The Andean goose is occasionally hunted, but it lives in areas that are only sparsely populated by humans. The seaweed goose is not subject to any hunting pressure, as its meat tastes unpleasant and the eggs are also not very tasty.
Attitude in Europe
The first mirror geese were kept in European zoos as early as the first half of the 19th century. The leading place here was the London Zoo, which also successfully bred some species for the first time. Some species were bred for the first time shortly after their introduction. However, breeding was unsystematic until the second half of the 20th century.
The British Wildfowl Trust undertook targeted breeding programs in the second half of the 20th century, so that the mirror geese shown in zoos today mainly come from such breeding programs. Many large European zoos that keep large numbers of ducks keep at least one species of mirror geese. However, overall keeping is on the decline, as European zoos are increasingly concentrating on breeding the Nordic geese species, which are also declining in numbers. Where they are kept, they are usually kept separate from other ducks because of their aggressiveness during the breeding season. Although the birds need a place to swim, they are not dependent on a pond for their well-being, so they are often cared for in ungulate enclosures. The sea kelp goose is the least featured species in zoos because it has been shown to be susceptible to disease in captivity. Many animals die of aspergillosis . Even in institutions such as the Wildfowl Trust, which has been given to many European or world first breeders, it was not possible to keep this species for a long period of time or to breed successfully. The world's first breeding was achieved in 1960 by a Californian ornithologist. However, only one chick grew up.
Systematics
The following five recent species belong to the genus of the mirror geese :
| German name | Scientific name | distribution | Hazard level Red List of IUCN |
Remarks | image |
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| Andean goose |
Chloephaga melanoptera ( Eyton , 1838) |
Andes plateaus at altitudes above 3000 meters, Peru , in the south of Argentina , in the west of Bolivia and in the north of Chile . |
 ( Least Concern - not at risk)
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monotypically 70 to 80 centimeters long, white plumage with black tail feathers and black wing tips, wings offset with black spots. Beak pink-red, feet red. Both sexes look the same. |
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| Magellangans |
Chloephaga picta ( Gmelin , 1789) |
Breeding bird in the south of South America . On the coasts of Tierra del Fuego , Chile, Patagonia or the Falkland Islands . |
( Least Concern - not at risk)
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2 subspecies: Large Magellan Gane ( C. p. Leucoptera ( Gmelin , 1789)) Small Magellan Gane ( C. p. Picta ( Gmelin , 1789)) 60 to 65 centimeters long. Males: white head, breast and belly plumage, remaining plumage gray, bill dark gray to black. Females: brown-gray plumage, feet orange to yellow. |
 male
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| Seaweed goose |
Chloephaga hybrida Sclater , 1857 |
southern Chile, on the coasts of Patagonia, Tierra del Fuego and the Falkland Islands. |
( Least Concern - not at risk)
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monotypically 55 to 65 centimeters long. Males: white plumage with black beak, a white spot around the nostrils, yellow feet. Females: Upper side of body dark brown, belly and tail white, gray lines across the chest and across the flanks, white eye ring, pink beak, yellow feet. |
 male
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| Gray headed goose |
Chloephaga poliocephala ( Molina , 1782) |
Mountain regions in the south of South America, including Chile and Argentina and the Falkland Islands. |
( Least Concern - not at risk)
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monotypically 53 to 66 centimeters long. Gray head, maroon plumage, white flanks offset by black lines. Bill gray-black, legs and feet orange-red. |
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| Red headed goose |
Chloephaga rubidiceps Sclater , 1861 |
Breeding areas on the moist grass plains of Tierra del Fuego and south of the Strait of Magellan, in Chile and on the Falkland Islands. In winter, the red-headed goose moves to the lowlands of southern Argentina. |
( Least Concern - not at risk)
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monotypically 45 and 50 centimeters long. Back and flanks gray-white, towards the tail darker and monochrome, belly cinnamon-colored. Legs yellow-orange, white eye ring. |
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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
