| Greylag Goose | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Anseriformes |
| Family: | Anatidae |
| Genus: | Anser |
| Species: | Anser anser |
The Greylag Goose or Graylag Goose (Anser anser) is a large bird in the family Anatidae. It is the ancestor of most of today's domestic geese.
Taxonomy[]
The Greylag Goose has two subspecies:
- Anser anser anser, the nominate subspecies.
- Anser anser rubrirostris, the eastern subspecies, is paler and larger, and its bill is pinkish rather than orange.
Description[]
| Measurements | |
|---|---|
| Length: | 75-90 cm (30-35 in) |
| Weight: | 3-4 kg (6.6-9 lbs) |
| Wingspan: | 150-180 cm (59-71 in) |
Adult and juvenile.
It is one of the largest geese in the genus Anser. The male is slightly larger than the female, but the two sexes are otherwise similar. The adult has grey-brown upperparts with pale feather margins. The underparts are cream-buff, and the belly and vent are white. The underwing appears bi-coloured, with dark remiges and pale covers. The legs, webbed feet, and bill are pinkish-orange in colour. The juvenile is similar, but with a more uniformly coloured plumage and greyish legs. The beak and tongue are equipped with tomia, teeth-like structures used to filter food from water. The sides of the neck appear grooved, due to the presence of long, narrow feathers.
Voice[]
This bird has a rich vocal repertoire, which includes loud shrieks and honks, low quacks, and a distinctive, trisyllabic "aang-gang-gang", usually given in flight.
Behavior[]
A group of wild Greylag Geese.
The Greylag Goose is one of the most studied species in the family Anatidae. Like all geese, this migratory bird is gregarious and lives in flocks that have a stable hierarchical structure. Displays of aggression are uncommon, as all members of the flock maintain a certain distance between each other. If a bird violates another's personal space, a small fight might break out, but episodes of actual violence are rare and mostly occur when the birds are competing for nesting sites, or when they are defending their broods. An aggressive goose will hiss and approach its opponent with its neck extended horizontally and its feathers puffed up.
The Greylag Goose is a strong, fast, and surprisingly maneuverable flier, but due to its weight, it needs a take off run in order to take flight, and prefers to land on water. Geese shake their heads vigorously to communicate their intention to take flight to the rest of the flock.
Feeding[]
Three individuals foraging.
The Greylag Goose is primarily herbivorous and granivorous, feeding on grass, sprouts, weeds, roots, cereals and aquatic plants. It may forage on the ground or while swimming, using its "toothed" bill to pluck stems or to filter food from the water. Occasionally it may also eat small invertebrates.
Breeding[]
These birds are monogamous and pair for life. During courtship, the male tries to impress the female by raising his head and tail and showing the white patches on his wings. He then approaches her and starts swimming next to her, frequently dipping his head under the water. Each time they are reunited after a period of separation, the two partners strengthen their pair bond with a display in which the male pretends to attack a rival, real or imaginary, before returning to his mate with his wings spread and his neck stretched, honking loudly. Both birds then vocalize to each other with their heads lowered, being careful never to approach each other frontally as this is a sign of hostility. Male homosexuality is quite common among Greylag Geese. Gander couples follow the same courtship rituals as heterosexual ones, and also pair for life.
Nesting occurs from March to July depending on the area. The Greylag Goose nests on the ground. The nest is made of twigs, straw and other plant material, and is lined with feathers. The clutch size is highly variable, but on average, a female goose will lay 5 creamy-white eggs. The eggs are incubated by the female alone for about a month. The goslings are covered in soft, yellow-brown down and are nidifugous, able to walk and swim shortly after hatching. A few hours after hatching, the young are led to the water by both parents. Usually, the female broods the young whilst the male stands guard, but both parents will defend their offspring fiercely if threatened. The young learn to fly at two months of life, but will stay with their parents until the following spring.
Due to the phenomenon known as imprinting, goslings become extremely attached to the first creature they come in contact with the moment they hatch. If their parents are not present at the time of their birth, the goslings may imprint on another animal or even on a human being, imitating their behaviour instead of that of their own species as a result.
Migration[]
Migration begins around September, with northern populations leaving earlier than southern ones. During migration and wintering, the geese form large flocks, which forage on meadows and stubble fields at day and gather on marshes, lakes and estuaries to roost at night. They are very prudent and generally do not wander too far from water, where they find shelter from predators.
Like many other large birds, Greylag Geese fly in a V-formation when migrating, which makes flight less laborious because the birds take advantage of the upwash lift force created by the wingtip vortices at the tip of the wings of the lead bird. Since the geese take turns leading the flock, the lead bird isn't necessarily the most dominant.
Distribution and Habitat[]
Feral Greylag and Canada Geese.
The Greylag Goose breeds in part Northern, Central and Eastern Europe (Iceland, the UK, part of Germany, Denmark, Poland, Scandinavia, part of the Balkan peninsula and Belarus) and in a large portion of Asia that includes the Caspian region, Kazakhstan, Mongolia, Russia and China. Its winters in the Mediterranean region, the Persian Gulf region, and certain areas of Pakistan, India, the Malay peninsula and Southern China, south of the Himalayas. Feral individuals can be found in the wild in Oceania and North America. Estuaries and lowland marshes are this species' natural habitat, but feral birds can be seen in city parks (Greylag Geese are particularly common in London and other British cities).
Relationship with humans[]
The Greylag Goose is the ancestor of the majority of modern western domestic goose races, whilst many Asian species are descended from the Swan Goose. The domestication of these birds began some 5000-6000 years ago. Geese are farmed for meat and eggs as well as for their down, which is used to line blankets, pillows and articles of clothing. Down farming is particularly common in Eastern Europe. Geese may also serve as guard animals, as they will honk loudly if approached by an intruder.
Despite being too large and fat to fly, many domestic geese have retained their migratory instincts. In autumn, geese have been seen gathering at the southern extremities of their fences, honking on for hours. In spring, they do the same at the northern part of their fences.