Description

The Genus Anser is made up of eleven species of grey geese, and is closely related to the black geese of the genus Branta.

The two groups of geese are medium to large birds, sitting between the larger swans (Cygnus) and the smaller series of ducks within the Anatidae family.

Geese are distinguished by long necks, strong webbed feet and powerful wings. They are strong fliers and are often seen high in the sky migrating in large groups (the familiar 'V' formation of the winter skies). They migrate for quite amazing distances, often over the width of the oceans (British Anser come from an area spread out from Greenland to Sibera).

Three white geese are sometimes placed into a separate Chen genus. The only member of this group to be found in Britain is the rare Snow Goose, Anser Caerulescens or Chen Caerulescens.

The Greylag Goose is the only member of the genus to breed in Britain, and there is also a winter migrant population of the same species.

The other four members of the genus to be found in Britain are all winter migrants. The Bean Goose comes from Scandinavia, the Pink-Footed Goose from Iceland and Spitsbergen and the White-Fronted Goose from Greenland and from Russia. The Snow Goose and Lesser White-Fronted Goose are both rarer visitors.

Classification
Order: Anseriformes (Geese, Swans, Ducks)
Family: Anatidae (Geese, Swans, Ducks)
Genus: Anser

Number of Species: Eleven (as of November 2014)

British Members of the Genus

Resident Breeder and Winter Migrant Populations
Greylag Goose Anser Anser

Winter Migrants
Pink-Footed Goose Anser Brachyrhynchus (some breeding)
Bean Goose Anser Fabalis 
White-Fronted Goose Anser Albifrons 

Scarce Migrants
Snow Goose Anser Caerulescens 

Vagrants
Lesser White-Fronted Goose Anser Erythropus