Greylag goose
| Greylag goose | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Greylag goose ( anser anser ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Anser anser | ||||||||||||
| ( Linnaeus , 1758) |
The gray goose ( Anser anser ) is a kind of the genus field geese ( Anser ) in the family of the duck birds (Anatidae). Greylag geese are among the most common waterfowl and are, after the Canada goose , the second largest species of geese in Europe . They are the wild ancestors of the domesticated domestic geese . Central Europe is considered to be the region where this goose was domesticated. The domesticated Asian hump geese go back to the related swan geese ( Anser cygnoides ) . The gray goose was described by Carl von Linné in his work Systema naturae in 1758 .
Appearance and reputation
The gray goose is lighter than the other gray geese. The neck looks relatively thick and, due to the stripy arrangement of the feathers, is slightly striped lengthways. The front wings are noticeably light and the belly has more or less pronounced black spots. The beak is relatively large and bulky. It reaches a length of 75 to 90 cm, a wingspan of 147 to 180 cm and a weight of 2 to 4 kg. Ganter are heavier than females and usually weigh between 3 and 4 kilograms. The lighter females, on the other hand, weigh 2 to 3.5 kilograms.
Newly hatched goose cubs are olive brown on top. This later changes to a gray-brown shade. The belly is a dark creamy white. The head, neck and sides of the body are greenish yellow. The juvenile plumage is a little more brown than that of adult birds. The belly is still without black spots. The beak is initially gray and later turns yellow. The feet are olive gray. In the first annual dress, the young birds largely resemble the adults. They have few or no black belly feathers.
Greylag geese can live up to 17 years. The best-known sound is the "ga-ga-ga", also known from domestic geese, but the very active gray goose has more than a dozen different vocalizations. There are individual differences. Some gray geese always call out in a very high pitched voice, while others make noisy creaking noises. However, they also have loud trumpeting calls in their repertoire. Occasionally there is a duet-like call between two individuals, with the geese calling alternately.
distribution
The greylag goose is a breeding bird of Northern and Eastern Europe as well as Asia.
During the migration, the gray goose can be found all over Europe. It breeds in Great Britain, all of Fennoscandinavia except in the areas far from the coast and in all of continental Europe northeast of a line from Dunkirk to Patras in Greece with a focus on the Netherlands , northern Germany , the southern coast of the Baltic Sea and in an area between Austria , Hungary and the Czech Republic .
The wintering areas of the greylag goose are on the west coast of the Iberian Peninsula, on the north coasts of Algeria and Tunisia and the coasts of the Adriatic Sea . Large populations of tens of thousands of geese regularly rest on the fallow meadows in the Neusiedlersee-Seewinkel National Park .
Way of life
Greylag geese are both diurnal and nocturnal. If they are frequently disturbed, they shift their foraging into the night. The preferred breeding ground for the gray geese are lakes with wide belts of reeds and adjacent meadows, which they use for grazing. Grazing places can also be far away. Breeding gray geese can also be found in bogs, on wooded islands and in floodplains. The greylag goose is a migratory bird that usually migrates south in winter. In the last few decades there has been a tendency for greylag geese to overwinter further and further north, especially in the Netherlands or in the breeding areas not too far north, and thereby become resident birds . This is favored by intensified agriculture, which offers enough food in harvested or newly sown fields even in winter, the lower hunting pressure than in southern Europe and possibly climate change . Until a few decades ago, almost all gray geese overwintered in the Marismas of the Guadalquivir and in Tunisia around Lake Ischkeul and in western Algeria . When they are on the move, they form a characteristic V-formation that is constantly in motion as individual geese change their places.
The migration routes of the gray goose are not genetically fixed, but are handed down in the various sub-populations. In addition to the train to the wintering quarters, there is a so-called moulting train that leads non-breeding animals to certain moulting sites . Since the 1960s, the Oostvaardersplassen have become the most important moulting site in Europe. Apart from the mating and breeding season, gray geese live in large flocks. Greylag geese mate in the autumn of the second calendar year, but rarely breed before they reach the fourth calendar year.
Greylag geese have a rich repertoire of comfort behavior that is typical of other waterfowl. These include submerging and also a kind of somersault, in which the bird dips forwards under itself and when emerging it performs a half turn around its longitudinal axis, so that it comes to swim against its original direction again.
Reproduction
.jpg)
Greylag geese usually show great loyalty to the partner, but mate again if the partner is lost. The breeding begins depending on the location in mid-March to the end of April. The nesting site is preferably on islands in freshwater waters, in swamp and marshland, on the banks of lakes or slowly flowing rivers. They breed in a very loose association of colonies, with a greater distance between the individual nests.
They build shallow nest hollows for breeding . Only in very humid breeding areas is the nest an accumulation of swamp plants. The actual nesting trough is only covered with a very thin layer of down. These downs are small, gray and a little lighter in the middle. In the south and south-east of their range, the breeding season usually begins towards the end of March. In more northern areas of distribution, gray geese do not lay eggs until late April. Greylag geese have only one clutch per year. If it is destroyed, there is no additional clutch. The clutch of wild gray geese usually consists of four to six eggs. They have a white or yellowish skin and an almost oval shape. The eggs are usually laid with a laying interval of a little more than 24 hours. The female breeds alone. Incubation begins when the last egg is deposited. The male stays near the nest during the breeding season. The young hatch after about 27 to 29 days and they take about 50 to 60 days to raise. The wing moult of the parent animals is in such a way that they are able to fly again a little later than the young. When they flee from the nest , this makes it easier for the young to learn flight maneuvers.
Most of the time the young stay with the parent animals until the next brood and can often be found with them later. Gray geese mainly recognize each other by their call. At large rest areas there is often a lot of shouting and hustle and bustle all night long, which helps to find family members.
Homosexual relationships can occur among male greylag geese. A female can be included in such a same-sex partnership; both males mate with the female, but one male is always dominant. The trio stays together while the young are raised. After that, the female separates from the group while the male pair stays together.
nutrition
Greylag geese look for their food mainly on land grazing. Sometimes they find their food swimming, but only very rarely dig .
Greylag geese live on plants, both land and water plants, mainly short grasses and herbs and, to a lesser extent, shrubs and roots . They are able to dig up parts of plants underground with their beak. In autumn, greylag geese prefer to seek out corn stubble fields where they can find high-energy grain food. However, they also graze in fields with rape and winter cereals. In spring they mainly use grassland and areas with winter cereals for food intake. In July and August, gray geese can often be seen on stubble fields.
In terms of nutrition, it is important that the areas on which the gray geese look for food have low vegetation in order to meet their safety requirements, but also because they can only feed on short grass and herbs. Natural pasture systems with large herbivores ( megaherbivores ) are ideal for this.
Inventory development
From a low point at the beginning of the 1970s, when the total European population comprised around 20,000 animals, the number of around 170,000 animals has increased in the mid-1980s to over 250,000 today (2003). This not only resulted in a denser settlement of traditional breeding areas, but also a significant expansion of the breeding area, especially in Germany and the Netherlands .
Others
- In 1988, Nobel Prize winner Konrad Lorenz wrote in his book Here I am - where are you? As he notes in his foreword, he wrote "the most complete treatment of the ethology of a higher animal", that is: all known behavior of the gray geese is precisely described. Previously, he had repeatedly helped his hand-reared gray goose Martina to literary fame. The behavior of gray geese is still being researched at the Konrad Lorenz Research Center today .
- Based on a legend ( Vita rhythmica s. Liudgeri ), the gray goose has been the attribute of St. Liudger since the 17th century .
- The asteroid (8435) Anser is named after her.
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 .
- Hans-Heiner Bergmann , Helmut Kruckenberg, Volkhard Wille: Wild geese - travelers between wilderness and pastureland. G. Braun, Karlsruhe 2006, ISBN 3-7650-8321-6 .
- Ilse Haseder , Gerhard Stinglwagner : Knaurs Großes Jagdlexikon , Augsburg 2000, ISBN 3-8289-1579-5 .
- Hartmut Kolbe: The world's ducks. 5th edition. Ulmer , Stuttgart 1999, ISBN 3-8001-7442-1 .
- Konrad Lorenz : The year of the gray goose. Piper 1982. (New edition 2003: Series Piper Volume 2637; text and photo book)
- Konrad Lorenz: Here I am - where are you? Ethology of the greylag goose. Piper, Munich / Zurich 1988.
- J. Madsen, G. Cracknell, Tony Fox: Goose Populations of the Western Palearchtic. Wetlands International, Wageningen 1999.
- Erich Rutschke: Wild geese, way of life - protection - use. Parey, Berlin 1997.
Web links
- Anser anser in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 2 of 2009.
- Videos, photos and sound recordings about Anser anser in the Internet Bird Collection
- Entry at the Swiss Ornithological Institute
- Ringed gray geese
- Gray goose feathers
- Report from the MPI for Ornithology Radolfzell.
- Video: Ethology of the Greylag Goose . Institute for Scientific Film (IWF) 1950, made available by the Technical Information Library (TIB), doi : 10.3203 / IWF / C-560 .
Individual evidence
- ↑ Kolbe, p. 111.
- ^ Sächsisches Landesamt für Umwelt und Geologie (Ed.): Wild geese and swans in Saxony - occurrence, behavior and management. Dresden 2006, publication as part of the public relations work of the Saxon State Office for Environment and Geology, p. 9.
- ↑ a b Hans-Heiner Bergmann; Hans-Wolfgang Helb; Sabine Baumann; The voices of the birds of Europe - 474 bird portrait with 914 calls and chants on 2,200 sonograms , Aula-Verlag, Wiesbaden 2008, ISBN 978-3-89104-710-1 , p. 47.
- ^ Collin Harrison and Peter Castell: Field Guide Bird Nests, Eggs and Nestlings. HarperCollins Publisher, 2002 revised edition, ISBN 0-00-713039-2 , p. 64.
- ↑ Haseder, p. 913.
- ↑ Bauer u. a, p. 71.
- ^ Sächsisches Landesamt für Umwelt und Geologie (Ed.): Wild geese and swans in Saxony - occurrence, behavior and management. Dresden 2006, publication as part of the public relations work of the Saxon State Office for Environment and Geology, p. 26.
- ^ Vita des heiligen Liudgers , website in the kirchensite.de portal , accessed on April 18, 2014.
