The Greylag Goose (Anser anser) is a large and robust member of the waterfowl family Anatidae, easily recognized by its mottled and barred grey and white plumage. It boasts an orange beak, pink legs, and a sizeable stature, measuring between 74 and 91 centimeters in length and weighing an average of 3.3 kilograms. This species is the progenitor of most domestic goose breeds and exhibits a wide distribution across Europe and Asia.
Adult Greylag Geese have a rotund body, a thick and long neck, and a large head and bill. Their legs and feet are pink, and their bill is orange or pink with a white or brown nail. The wingspan ranges from 147 to 180 centimeters. Males are typically larger than females, and the eastern subspecies rubirostris is larger than the nominate subspecies. The plumage is greyish brown with a darker head and paler underparts, with black spotting that varies among individuals. Juveniles can be identified by their lack of black speckling and greyish legs.
Greylag Geese breed in a variety of wetland habitats, including moorlands, marshes, lakes, and coastal islands. They prefer areas with dense vegetation for cover. In winter, they occupy semi-aquatic habitats such as estuaries, marshes, flooded fields, and agricultural lands.
The Greylag Goose has a Palearctic distribution, with the western subspecies breeding from Iceland to central Europe and the eastern subspecies from Romania to northeastern China. Northern populations often migrate southwards to spend the winter in warmer regions, while many populations are resident year-round.
Greylag Geese are known for their lifelong monogamous pair bonds. They are gregarious and form flocks, which provides safety in numbers. Family groups stay together, migrating southwards in autumn and separating the following year. They are herbivorous, feeding mainly on grasses, and can cause damage to agricultural crops.
The call of the Greylag Goose is a loud cackling, similar to that of domestic geese. They use various calls for different situations and can recognize individual geese by voice. Flocks produce a sound reminiscent of baying hounds.
Greylag Geese mate for life and nest on the ground among vegetation. They lay a clutch of three to five eggs, which the female incubates. Both parents defend and rear the young, who are precocial and leave the nest shortly after hatching.
The Greylag Goose can be confused with other grey geese of the genus Anser, but its larger size, bulkier body, and specific plumage pattern help distinguish it.
The diet consists mainly of grasses, but also includes grains, tubers, and occasionally small aquatic animals. They have adapted to feed on agricultural crops, which has led to conflicts with farmers.
The Greylag Goose is currently listed as Least Concern by the IUCN, indicating a stable and widespread population. However, some local populations may face threats from habitat loss and conflicts with agriculture.