Greylag geese travel to their northerly breeding grounds in spring, nesting on moorlands, in marshes, around lakes and on coastal islands.

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.

[3] 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.

[8] 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.

[9] The plumage of the greylag goose is greyish brown, with a darker head and paler breast and belly with a variable amount of black spotting.

It has a white line bordering its upper flanks, and its wing coverts are light coloured, contrasting with its darker flight feathers.

The nominate subspecies breeds in Iceland, Norway, Sweden, Denmark, Finland, the Baltic States, northern Russia, Poland, eastern Hungary, Romania, Germany and the Netherlands.

It also breeds locally in the United Kingdom, Belgium, Austria, the Czech Republic, Slovakia, North Macedonia and some other European countries.

[14] Historically, European birds generally migrated southwards to spend winter in southern Europe and North Africa,[14] but in recent decades many instead overwinter in or near their breeding range, even in Scandinavia.

[19] 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 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.

[14] Large numbers of immature birds congregate each year to moult on the Rone Islands near Gotland in the Baltic Sea.

[15][16][21] Wintering grounds closer to home can therefore be exploited, meaning that the geese can return to set up breeding territories earlier the following spring.

Due to extensive damage caused to crops, the hunting season for the greylag goose in the Orkney islands is now most of the year.

Short, actively growing grass is more nutritious and greylag geese are often found grazing in pastures with sheep or cows.

[25] The tubers of sea clubrush (Bolboschoenus maritimus) are also taken as well as berries and water plants such as duckweed (Lemna) and floating sweetgrass (Glyceria fluitans).

In wintertime they eat grass and leaves but also glean grain on cereal stubbles and sometimes feed on growing crops, especially during the night.

After the eggs hatch, some grouping of families occur, enabling the geese to defend their young by their joint actions, such as mobbing or attacking predators.

[24] After driving off a predator, a gander will return to its mate and give a "triumph call", a resonant honk followed by a low-pitched cackle, uttered with neck extended forward parallel with the ground.

[14] Young greylags stay with their parents as a family group, migrating with them in a larger flock, and only dispersing when the adults drive them away from their newly established breeding territory the following year.

[20] Greylags leave their northern breeding areas relatively late in the autumn, for example completing their departure from Iceland by November, and start their return migration as early as January.

For that festival, in Thomas Bewick's time, geese were driven in thousand-strong flocks on foot from farms all over the East of England to London's Cheapside market, covering some 13 or 14 kilometres (8 or 9 mi) per day.