The greylag goose (Anser anser) is a species of large goose in the waterfowl family Anatidae and the type species of the genus Anser. It has mottled and barred grey and white plumage and an orange beak and pink legs. A large bird, it measures between in length, with an average weight of . Its distribution is widespread, with birds from the north of its range in Europe and Asia often migrating southwards to spend the winter in warmer places, although many populations are resident, even in the north. It is the ancestor of most breeds of domestic goose, having been domesticated at least as early as 1360 BCE. The genus name and specific epithet are from anser, the Latin for "goose". In the USA, its name has been spelled "graylag".

Greylag geese travel to their northerly breeding grounds in spring, nesting on moorlands, in marshes, around lakes and on coastal islands. They normally mate for life and nest on the ground among vegetation. A clutch of three to five eggs is laid; the female incubates the eggs and both parents defend and rear the young. The birds stay together as a family group, migrating southwards in autumn as part of a flock, and separating the following year. During the winter they occupy semi-aquatic habitats, estuaries, marshes and flooded fields, feeding on grass and often consuming agricultural crops. Some populations, such as those in southern England and in urban areas across the species' range, are primarily resident and occupy the same area year-round.

Taxonomy

The greylag goose was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. He placed it with the ducks in the genus Anas and coined the binomial name Anas anser. The specific epithet is Latin meaning "goose". The greylag goose is now one of 11 geese placed in the genus Anser that was erected in 1860 by the French naturalist Mathurin Jacques Brisson. It is the type species of the genus.

Two subspecies are recognised: A. a. anser, the western greylag goose, which breeds in Iceland and northern and central Europe, and A. a. rubrirostris, the eastern greylag goose, which breeds in Romania, Turkey, and Russia eastwards to northeastern China. though this is not an accepted subspecies name.

Description

thumb|left|Head of an adult

The greylag is the largest and bulkiest of the grey geese of the genus Anser, but is more lightly built and agile than its domestic relative. It has a rotund, bulky body, a thick and long neck, and a large head and bill. It has pink legs and feet, and an orange or pink bill with a white or brown nail (hard horny material at tip of upper mandible). Males are generally larger than females, with the sexual dimorphism more pronounced in the eastern subspecies A. a. rubirostris, which is larger than the nominate subspecies on average. Asian birds migrate to Azerbaijan, Iran, Pakistan, northern India, Bangladesh and eastward to China.

In North America, there are both feral domestic geese, which are similar to greylags, and occasional vagrant greylags. and a similar situation has occurred in Australia, where feral birds are now established in the east and southeast of the country.

In their breeding quarters, they are found on moors with scattered lochs, in marshes, fens and peat-bogs, besides lakes and on little islands some way out to sea. They like dense ground cover of reeds, rushes, heather, bushes and willow thickets. In their winter quarters, they frequent salt marshes, estuaries, freshwater marshes, steppes, flooded fields, bogs and pasture near lakes, rivers and streams. They also visit agricultural land where they feed on winter cereals, rice, beans or other crops, moving at night to shoals and sand-banks on the coast, mud-banks in estuaries or secluded lakes. Wintering grounds closer to home can therefore be exploited, meaning that the geese can return to set up breeding territories earlier the following spring.

The greylag goose has become a pest species in several areas where its population has increased sharply. In Norway, the number of greylag geese is estimated to have increased three- to five-fold between 1995 and 2015. As a consequence, problems for farmers caused by goose grazing on farmland have increased considerably. This problem is also evident for the pink-footed goose. In the Orkney islands the population has increased dramatically: there were 300 breeding pairs, increasing to 10,000 in 2009, and 64,000 in 2019. Due to extensive damage caused to crops, the hunting season for the greylag goose in the Orkney islands is now most of the year.

Behaviour

Greylag geese are largely herbivorous and feed chiefly on grasses. Short, actively growing grass is more nutritious and greylag geese are often found grazing in pastures with sheep or cows.

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Greylag geese (Anser anser) on nest Denmark.jpg|pair on nest, Denmark

Nyári lúd fészekalja.jpg|eggs in the nest, Hungary

Anser anser EM1B9595 (33952161753).jpg|female with goslings, Sweden

Greylag goose (Anser anser) in flight Marken.jpg|adult in flight, Netherlands

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Greylag geese tend to pair bond in long-term monogamous relationships. Most such pairs are probably life-long partnerships, though 5 to 8% of the pairs separate and re-mate with other geese. At least in Europe, patterns of migration are well understood and follow traditional routes with known staging sites and wintering sites. The young learn these locations from their parents which normally stay together for life.

In human culture

Geese are important to multiple culinary traditions. The meat, liver and other organs, fat, skin and blood are used culinarily in various cuisines.

The greylag goose was once revered across Eurasia. It was linked with the goddess of healing, Gula, a forerunner of the Sumerian fertility goddess Ishtar, in the cities of the Tigris-Euphrates delta over 5,000 years ago.

Further reading

  • Ageing and sexing (PDF) by Javier Blasco-Zumeta & Gerd-Michael Heinze
  • Greylag Goose at RSPB A to Z of UK Birds
  • Greylag Goose pictures Wildlife Greylag Goose photos- adult with nestlings and voice at nature-pictures.org
  • Greylag Goose Educational video from Avi Birds