Golden bell
| Golden bell | ||||||||||||
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Golden blue duck |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Bucephala clangula | ||||||||||||
| ( Linnaeus , 1758) |
The Goldeneye ( Bucephala clangula ) is a holarctic spread of bird from the family of ducks (Anatidae). Their distribution area is the northern coniferous forest zone . The short neckedness and the relatively large head give the species a stocky appearance.
The golden blue duck occurs in two subspecies from Europe to Siberia to America. Among the sea ducks , it is the most suitable species for keeping. It is therefore shown relatively often in zoological gardens .
In the north of Central Europe, the golden bell is a widespread, but not frequent breeding, summer and sometimes annual bird. She is also a frequent migrant and winter visitor.
description
The 45 to 50 cm tall golden golden bell weighs 500 to 1,300 g and has a wingspan of up to 80 cm. The male has black and white plumage and a dark green head. There is a white spot between the eye and the black beak. The bright yellow eyes of the males, which are also the reason for the English name "Goldeneye", are striking. In plumage the drakes a similar plumage of the females have. However, adult males can be distinguished from females by the striking wing pattern.
The female has gray plumage and a dark brown head with no white spot. They differ from the very similar females of the spatula by the large white field on the middle arm-covers. The legs are reddish in color. In females, the irises are pearly white.
Golden pelts that are not yet sexually mature wear a dress like the adult females, and are generally a little more brown. The white color field in the wing is smaller and less noticeable. The iris is light gray in color. The males among the young birds can be distinguished from the young females by their slightly larger body size. In the first magnificent dress, the drakes still have a dark brown head with black feathers. In some individuals the white spot on the cheek is only hinted at at this point.
The American subspecies Bucephala clangula americana is slightly larger than the European nominate form B. c. clangula . The golden bell can be up to 17 years old. Especially in spring she is very happy to call. During courtship, the male calls a nasal rätsch-rärr and quikiikirr . The courtship also includes a noticeably loud splash of water, in which the drake pushes backwards with both feet (so-called instrumental sound ). The call of the female sounds like "garr garr" or "graar grar", which can also be heard by flying golden ducks. Females looking for nest holes give a long row of gärk-gärk .
distribution
The golden jack lives in Eastern , Central and Northern Europe , Asia and North America . To the north it penetrates to the arctic tree line. The southern limit of their distribution area is the forest steppe zone. However, there are a large number of island-like occurrences further south. The European distribution area includes large parts of Scandinavia, parts of the North German Plain, northern and central Poland and the European part of Russia. There are isolated breeding occurrences in southeast Germany, in southern Bohemia, in the Dnepr estuary on the Black Sea and in the Danube Delta.
habitat
She feels very comfortable in standing water , such as lakes and ponds . Originally it was a characteristic of nutrient-poor, oligotrophic waters. Today in Central Europe, the golden-headed duck also colonizes nutrient-rich, polytrophic waters. In Upper Lusatia, for example, it is observed in eutrophic fish ponds. They can also be observed in slowly flowing waters if there are forests and breeding caves.
Outside of the breeding season, it can also be found in larger inland waters. During this time it also occurs on rivers, in sea bays and on quiet sections of the open coast.
nutrition
The golden-bellied duck feeds on snails , crustaceans , parts of plants , small fish , insects and their larvae . She can dive up to eight meters deep to steal her meals there.
The gizzard of Schellente, in comparison with Heron and Tafelente a relatively weakly pronounced circular muscle. Therefore, unlike these two species, it is not able to generate the pressures necessary to break up larger mollusc shells . The greater gastric stones are also missing in the greater pomeranian stomach and because of its pointed and narrow beak it is only able to grab smaller prey. However, with this beak it can also reach into crevices and gaps between stones. Their preferred feeding grounds are therefore bodies of water with a gravelly and stony bottom.
Reproduction
An extensive repertoire of courtship poses and courtship gestures is part of the golden ducks' courtship. The first males show the first characteristic behavior of courtship as early as autumn. From December the drakes gather in small groups of between two and eight animals and court together near individual females. The females seem indifferent to the courtship. However, the males respond to the females by following a female swimming away and continuing courtship in their vicinity. Pair formation and copulation still take place in the winter quarters. However, the common zone continues until the arrival in the breeding areas and only comes to an end when the individual pairs have found a suitable breeding cave and retreat to a stretch of water.
The golden eyed duck breeds in tree holes , old black woodpecker holes and nesting boxes . The hole in the cave should be over four inches and the cave should be about 18 inches deep. Suitable breeding caves can be found in Central and Eastern Europe, especially in old oaks. Blue ducks, however, are very happy to accept breeding aids in the form of artificial nesting holes and even prefer them to natural ones. The breeding cave can be located directly above the ground, but breeding caves at a height of eight to ten meters are also accepted by this species of duck.
The breeding season extends from April to July. The female lays eight to eleven green-blue eggs at intervals of one to two days , which are incubated by the female for 30 days until the black-and-white chicks hatch. Since there is an intraspecific brood parasitism in the golden-tailed duck , clutches can contain more than 20 eggs. Females are also able to successfully incubate such large clutches. The female golden ponds sit very firmly on their clutch, i. that is, they rarely allow themselves to be disturbed by their nest. She fends off enemies with a hissing beak. The drake only stays near the breeding cave at the beginning of the breeding phase. Before the young have hatched, the drake leaves the breeding area and migrates to the moulting areas.
The female causes the young to leave the brood cavity as soon as the last young animal has hatched from the egg and has dried off. The golden golden duck, waiting on the ground or in the water, then lures the young with a specific call, which causes one young after the other to appear at the loophole and leap after the mother duck. In order to be able to climb out of the brood cavity, the bell-mouth chicks have pointed, curved claws on their feet, with which they are able to climb up the inner wall of the brood cavity. They try to make the jump, which can be eight to ten meters depending on the height of the breeding cave, by bending the wing stumps and spreading the webbed feet. The family can change the body of water several times while the young are raised. The young birds fledge after eight to nine weeks. The young birds are independent even before they fled and disperse very early on. In the second year of life, the golden-bellied duck becomes sexually mature.
Duration
The European population is estimated at around 250,000 breeding pairs. The IUCN puts the total population at over 2 million animals. The species is considered harmless. A research team that, on behalf of the British environmental authority and the RSPB, examined the future distribution of European breeding birds on the basis of climate models, however, assumes that the golden duck will disappear over a wide area in the southern region by the end of the 21st century as a result of global warming and western part of its range will come. According to this forecast, the distribution area will decrease significantly and shift to the north.
literature
- Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 1: Nonpasseriformes - non-sparrow birds , Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-647-2
- T. Bartlett: Ducks and geese - a guide to management. The Crowood Press, 2002, ISBN 1-85223-650-7
- Hartmut Kolbe: The world's ducks. Ulmer Verlag 1999, ISBN 3-8001-7442-1 .
- Erich Rutschke: The wild ducks of Europe - biology, ecology, behavior , Aula Verlag, Wiesbaden 1988, ISBN 3-89104-449-6 .
Web links
- Bucephala clangula in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings of Bucephala clangula in the Internet Bird Collection
- Golden golden feathers
Individual evidence
- ↑ a b Kolbe, p. 308
- ↑ Bauer et al., P. 136
- ↑ Hans-Heiner Bergmann; Hans-Wolfgang Helb; Sabine Baumann; The voices of the birds of Europe - 474 bird portraits with 914 calls and chants on 2,200 sonograms , Aula-Verlag, Wiesbaden 2008, ISBN 978-3-89104-710-1 ; P. 72. This source has been used for the onomatopoeic description of the voices.
- ↑ Rutschke, p. 267
- ↑ Rutschke, p. 38
- ↑ Rutschke, pp. 267 and 268
- ↑ Rutschke, p. 269
- ↑ Rutschke, p. 270
- ^ Brian Huntley, Rhys E. Green, Yvonne C. Collingham, Stephen G. Willis: A Climatic Atlas of European Breeding Birds , Durham University, The RSPB and Lynx Editions, Barcelona 2007, ISBN 978-84-96553-14-9 , P. 95