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Anser (bird)

life science Maturity 11-13 Next article →

The genus *Anser* represents a diverse group of waterfowl found throughout the Northern Hemisphere.

These birds are classified within the subfamily Anserinae, which includes true geese and swans. They belong to the broader family known as Anatidae. The genus is characterized by a Holarctic distribution, meaning they inhabit many parts of the northern regions. Most species thrive in open, wet habitats during the subarctic and cool temperate summers.

Some species extend their breeding grounds further south into warmer temperate zones.

To survive changing seasons, many *Anser* species follow a strict migratory pattern. They typically breed in northern latitudes during the summer months. When winter approaches, they migrate toward more temperate regions. They often seek areas where the temperature stays between 0 °C and 5 °C.

This movement ensures they remain in environments suitable for their survival. Their physiological adaptations allow them to navigate these vast distances annually.

Physically, the species within *Anser* exhibit a wide range of sizes and appearances. The largest members include the bean goose, the greylag goose, and the swan goose. These larger birds can reach significant weights, though domestic versions are often much heavier.

Greylag Goose - St James's Park, London - Nov 2006
Greylag Goose - St James's Park, London - Nov 2006

Conversely, the Ross's goose and the lesser white-fronted goose are among the smallest. Most species possess pink or orange legs and feet. Their bills may be black, pink, or orange, or a combination of these colors.

Bar-headed Goose (Anser indicus) (52767406084)
Bar-headed Goose (Anser indicus) (52767406084)

Most have grey or white bodies with black primary feathers on their wings.

Taxonomy and the history of the genus have undergone several important changes. The name *Anser* was introduced by the French zoologist Mathurin Jacques Brisson in 1760. The term is derived from the Latin word for goose. It was established using the greylag goose as the type species.

Anser cygnoides, Ozero Stepnoye, Ivolginskiy, Buryatia Republic, Russia 1 (cropped)
Anser cygnoides, Ozero Stepnoye, Ivolginskiy, Buryatia Republic, Russia 1 (cropped)

Previously, the "white geese" like the snow goose were placed in a separate genus called *Chen*. However, scientists now include them in *Anser* to maintain correct evolutionary groupings. This ensures the genus is not paraphyletic, which would happen if the bar-headed goose were excluded.

Understanding the evolutionary relationships of these birds has been a complex scientific challenge. This difficulty arises because of rapid radiation during the Pleistocene epoch and frequent hybridization.

In 2016, a study by Ottenburghs and colleagues used exonic DNA sequences to map these relationships. Their work helped clarify how different species are connected through their genetic history. A follow-up study in 2023 further refined the details of the bean goose complex. This research revealed that the pink-footed goose is most closely related to the taiga bean goose. This was a significant finding, as it changed the previous belief that it was closer to the tundra bean goose.

Humans have interacted with *Anser* geese for many centuries, particularly through domestication. Two species have been specifically raised as poultry for commercial use. European domestic geese are descended from the greylag goose.

Snow goose in Central Park (33138)
Snow goose in Central Park (33138)

Meanwhile, Chinese and some African domestic geese are descended from the swan goose. While many species have benefited from hunting protections since the 19th century, others face modern risks. Habitat loss and over-hunting remain serious concerns for certain populations.

Conservation status varies significantly across the eleven living species. While many are not considered threatened, some require urgent attention. The lesser white-fronted goose and the swan goose are both listed as Vulnerable.

Additionally, the emperor goose is classified as near-threatened. In some regions, large flocks of geese can cause conflicts with farmers by grazing on crops during the winter. Monitoring these populations is vital for maintaining the biodiversity of northern wetland ecosystems.

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🖼️ Images & Media (21)
File:The geese of Europe and Asia (Anser indicus).jpg
The geese of Europe and Asia (Anser indicus).jpg
File:The geese of Europe and Asia (Anser canagicus).jpg
The geese of Europe and Asia (Anser canagicus).jpg
File:The geese of Europe and Asia (Anser caerulescens).jpg
The geese of Europe and Asia (Anser...
File:The geese of Europe and Asia (Anser anser).jpg
The geese of Europe and Asia (Anser anser).jpg
File:The geese of Europe and Asia (Anser cygnoides).jpg
The geese of Europe and Asia (Anser cygnoides).jpg
File:The geese of Europe and Asia (Anser serrirostris serrirostris).jpg
The geese of Europe and Asia (Anser...
File:The geese of Europe and Asia (Anser brachyrhynchus).jpg
The geese of Europe and Asia (Anser...
File:The geese of Europe and Asia (Anser fabalis).jpg
The geese of Europe and Asia (Anser fabalis).jpg
File:The geese of Europe and Asia (Anser albifrons).jpg
The geese of Europe and Asia (Anser albifrons).jpg
File:The geese of Europe and Asia (Anser erythropus).jpg
The geese of Europe and Asia (Anser...
File:Bar-headed Goose (Anser indicus) (52767406084).jpg
Bar-headed Goose (Anser indicus) (52767406084).jpg
File:Emperor goose on a tundra pond (53707932863).jpg
Emperor goose on a tundra pond (53707932863).jpg

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