Bean Goose

Bean Goose
	Bean goose ( Anser fabalis )
Systematics
Order :	Goose birds (Anseriformes)
Family :	Duck birds (Anatidae)
Subfamily :	Geese (anserinae)
Tribe :	Real geese (Anserini)
Genre :	Field geese ( anser )
Type :	Bean Goose
Scientific name
	Anser fabalis
	( Latham , 1787)

The bean goose ( Anser fabalis ) or reed goose is a real goose (Anserini) belonging to the field geese ( Anser ). It looks very similar to the short-billed goose ( Anser brachyrhynchus ), but today it is regarded as a separate species . In the wild they can be recognized by their two-syllable flight call, a loudly trumpeted "kayak, kajak". The species was first described by John Latham in 1787 . In Germany she can be found in large numbers as a winter guest from the end of September .

The bean goose is a migrant and winter visitor, especially in northern Central Europe. Occasional brood settlements, possibly originating from captive refugees or injured wild birds, have existed in the Netherlands since 1993.

Surname

The German term Saatgans has become established because you can often see this goose looking for food in meadows and grain fields. The scientific Anser fabalis translates as bean goose . There are two possible explanations for this name. For one, beans can be part of your diet. In adult geese of this species there are two narrow crescent-shaped or bean-shaped small white stripes next to the beak root.

Appearance

The plumage is basically gray-brown, but dark brown on the neck and the angular head. This distinguishes the bean goose from the white- fronted goose ( Anser albifrons ) and the gray goose ( Anser anser ). Breast and belly are light brown, towards the tail even whitish, the wings on the other hand dark brown again. Fine white lines can be found in the plumage on the flanks as well as on the outside of the wings and on the tip of the tail.

The beak, which is provided with serrated side edges, is black at the base and the tip, in between there is an orange marking of different widths depending on the subspecies. The webbed feet are of the same color. Eye color is dark brown.

The downy chicks are olive brown on the body surface. The sides of the body are green-yellow, the underside of the body is whitish. A dark stripe runs through the eye. By the time the young birds fledge, the beak is dark gray and has a light pink to cream colored nail. The young animals, on the other hand, have an inconspicuous olive-brown camouflage dress made of down feathers with black stripes in the head region. Feet and beak are mouse gray.

The average size of the birds is 65 to 90 cm with a wingspan of 140 to 170 cm; Similar in appearance to the male, the female is usually somewhat smaller. Adult animals weigh around 3 to over 4 kg. Ringed bean geese are known to be over twenty years old in the wild.

voice

The bean goose is much less willing to shout than the gray goose or the white- fronted goose . The triumphant cry of a couple is emphatically nasal cackling and trumpeting and sounds like a ga gi gig cooked . A geese-typical nasal call can be heard from flying bean geese , which sounds like gaga or agagag , more rarely like käjak or gock .

nutrition

Bean geese eat cranberries in autumn.

The food of the bean geese in their breeding area consists of lichens , grasses , herbs and aquatic plants, in autumn also of berries such as cranberries , bogberries and beans . Their English name "bean goose" and their Latin epithet fabalis (Latin: faba = bean) come from the latter .

In their wintering areas they eat roots , especially couch grass , potatoes and cereal grains, grasses, and especially also harvest residues from harvested fields (especially high-energy sugar beet pulp or maize). Bean geese can also be found on grain crops, where they can cause feeding damage if the threshold value of 1500 geese days per hectare is exceeded.

The young birds, on the other hand, not only feed on flowers and buds , but also non-vegetarian on insects , molluscs , small crabs and even fish eggs.

habitat

In their breeding areas, bean geese live in pairs either in the taiga in the middle of coniferous and birch forests , in moors and forest swamps, on reed islands and on calm waters or further north in the bush, moss or even lichen tundra , there mostly, but not always, near lakes and river plains, preferably in steep, inaccessible bank areas. However, breeding pairs can also be found far away from water on extensive gravel fields.

In their wintering areas they live in large colonies and prefer harvested arable land (especially sugar beet and corn fields), meadows and pastures. They like to sleep on open water, in winter also on ice, and hike back and forth between their sleeping and pasture places, sometimes more than ten kilometers, every day.

distribution

Distribution of the Bean Goose:

Breeding areas

migration

Wintering areas

Bean and white-fronted geese in Mecklenburg

Bean geese are migratory birds that have established regular migratory traditions and, depending on the family, repeatedly visit the same breeding and wintering areas.

The former extend in the northern tundra and taiga from northern Scandinavia in the west to eastern Siberia and the Sea of Okhotsk in the east.

The winter areas are extremely diverse. In Central Europe, they include in particular southern Sweden , Denmark and the German Baltic Sea coast , the North German Plain with the Lower Rhine between Wesel and Emmerich am Rhein and the Netherlands , isolated parts of British East Anglia and Southwest Scotland , plus an area close to the Alps from western Austria via Switzerland to far into France and large regions in the lowlands of the Danube . In cold winters, they are drawn down the Atlantic coast to Spain and Portugal , rarely even to Morocco .

In the Mediterranean area, the French Riviera and the Italian and Croatian Adriatic coasts are part of their wintry habitat, and further east also the Bulgarian - Romanian coastal regions of the Black Sea .

East Siberian populations, on the other hand, overwinter in Central Asia , particularly Iran , or even further east in the People's Republic of China , Southeast Asia , Korea and Japan .

Reproduction

Egg, Museum Wiesbaden collection

Bean geese look for a partner in their second or third year of life in the wintering area, with whom they then stay together for life.

Around March they move north and meet with the birds that breed in the taiga at the end of April, with the tundra brooders, on the other hand, only in mid to late May in their breeding area, which at this time is often still covered by snow and ice. The bean goose is one of the arctic geese species that return to their breeding grounds earliest. In the time remaining until the snow melts, mating fights between the males sometimes occur. Mating takes place in the water after a short foreplay, in which both partners indicate their willingness to mate by submerging their necks. To do this, the male mounts the female, which usually sinks into the water. The ritual is completed by stretching the neck and flapping the wings together.

The female then builds the nest under bushes and bushes, in the reeds or in the nesting area in the swamp on low, dry hills and feeds it with blades of grass, moss and lichen , and later also with its down feathers. These down feathers are brown-gray and have a lighter center. Bean geese raise only one clutch per year.

The laying of two to eight, but mostly four to six yellowish eggs begins in the taiga in mid-May, in the tundra around mid-June; they are not incubated by the female until the last egg has been laid, so that the young hatch in close proximity to one another, in the tundra after 25 days, in the taiga after around 28 to 29 days. As with all real geese, the male does not participate in the breeding business, but guards the females and brood. In serious danger, both animals crouch flat on the ground.

After about six weeks the young are fledged, at this time the older animals also have their taking place mostly in July and August Mauser behind. (Non-breeding animals start moulting together from June, for example to the Russian North Sea island of Novaya Zemlya , where they then reside in large flocks.) The family group then flies back to the winter quarters with other geese at the beginning of September, where the young geese continue for the next Stay with their parents into the year. At two to three years of age, they themselves become mature for breeding. The oldest ringed wild bird was 29 years old.

The Bean Goose mated not only with members of their own species: from hybrids with the white-fronted goose ( Anser albifrons ), the Gray Goose ( Anser anser ), the Pink-footed Goose ( Anser brachyrhynchus ), the snow goose ( Anser caerulescens ) and even to the sea geese belonging Barnacle Goose ( Branta leucopsis ) is reported.

Danger

As the third most common wild goose, the bean goose is not endangered in its entirety; the population in Europe is estimated at around 200,000 animals. In agriculture , it causes regional problems through its consumption of fresh seed grain, which is why in Germany it is considered huntable game birds , which can be shot in November and December. In view of the problematic development of the forest bean geese population, there has been a year-round hunting ban on bean geese in the state of Brandenburg since 2019, but it is still not in the particularly important Mecklenburg-Western Pomerania.

The populations of the big-billed bean goose ( Anser fabalis serrirostris ) and Middendorff's bean goose ( Anser fabalis middendorffi ), both subspecies of the bean goose, are considered endangered by hunting and loss of habitat.

Subspecies

Tundra Bean Goose

A total of five subspecies are distinguished, which, however, overlap in broad areas and therefore cannot be clearly differentiated from one another. These five subspecies are often divided into two groups, namely the tundra and forest bean geese, which are now often viewed as separate species .

There are two forms in Western Europe:

The stocky-looking Anser fabalis rossicus (also known as the tundra bean geese) has a relatively short neck and a thick, short beak. Their plumage is strikingly dark gray with a brown tint. There is a striking contrast between the dark brown head and the gray brown neck. Their wingspan is 140 to 170 centimeters. It breeds on the tundra in northern Russia and northwestern Siberia from the Kanin to the Taimyr Peninsula and is the most common subspecies of the bean goose. There are very many of them in Germany. Their resting populations have increased. Among other things, it benefited from the flooding of former lignite opencast mines in northwest Saxony and in Lusatia, because this created numerous new resting waters.

The longer-necked Anser fabalis fabalis , which belongs to the forest goose, has a rather narrow beak, a longer neck and is overall larger than the tundra bean goose. It has its breeding area in the taiga from Scandinavia to the Urals . Forest bean geese are characterized by a clearly defined orange band on the otherwise black beak. The forest bean goose is observed in small numbers in Germany every year. There are declines in the population, which have also led to a significant reduction in the size of the wintering area. The most important wintering areas for this species are in north-east Germany, Sweden and Denmark.

Three other subspecies of the bean goose are described worldwide:

the Johansen Bean Goose ( Anser fabalis johanseni ), which breeds in the taiga and Strauchtundra of Siberia east of the Urals to Lake Baikal ,

the Middendorff's Bean Goose ( Anser fabalis middendorffi ), which is found in the taiga areas east of Lake Baikal and

the thick-billed bean goose ( Anser fabalis serrirostris ), which lives in the tundras of northeast Siberia from the Lena river delta to the region around the Russian city of Anadyr in summer .

The subspecies johanseni and middendorffi belong to the forest bean goose, serrirostris to the tundra bean goose.

Since forest geese and tundra sand geese breed in different regions, geographical contact in the breeding areas is limited. The extent to which reproductive barriers also exist has not yet been clarified. Differences in the two groups could be sustained solely because of the strongly divergent selection pressure in the respective breeding areas without a reproductive barrier between the two groups.

swell

↑ Bauer u. a., p. 62
↑ Viktor Wember: The names of the birds in Europe - meaning of the German and scientific names. Aula-Verlag, Wiebelsheim 2007, ISBN 978-3-89104-709-5 , p. 79.
↑ Uspenski, p. 39
↑ Collin Harrison, Peter Castell: Field Guide Bird Nests, Eggs and Nestlings. HarperCollins Publisher, 2002, ISBN 0-00-713039-2 , p. 65.
↑ ^a ^b ^c Saxon State Office for Environment and Geology (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. 11.
↑ https://djz.de/wp-content/uploads/sites/3/2019/07/BbgJagdDV_5_7_2019.pdf
↑ Alderfer, p. 4.
↑ Bauer u. a., p. 61

literature

Hans-Günther Bauer, Einhard Bezzel , 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 Verlag, Karlsruhe 2006, ISBN 3-7650-8321-6 .
J. Madsen, G. Cracknell, Tony Fox: Goose Populations of the Western Palearctic. Wetlands International, Wageningen 1999, ISBN 87-7772-437-2 .
Johan H. Mooij: Development and management of wintering geese in the Lower Rhine area of North Rhine Westfalia / Germany. In: The ornithological station. 37: 55-77 (1993).
Erich Rutschke: Wild geese, way of life - protection - use. Parey, Berlin 1997, ISBN 3-8263-8478-4 .
H. Kolbe: The duck birds of the world. 5th edition Eugen Ulmer Verlag, 1999, ISBN 3-8001-7442-1 .
SM Uspenski: The wild geese of Northern Europe. Westarp Wissenschaften-Verlagsgesellschaft, Hohenwarsleben 2003, ISBN 3-89432-756-1 . (Reprint of the 1st edition from 1965)