Mute goose

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Mute goose
Male Mute Goose (Sarkidiornis melanotos sylvicola)

Male Mute Goose ( Sarkidiornis melanotos sylvicola )

Systematics
Class : Birds (aves)
Family : Duck birds (Anatidae)
Subfamily : Half geese (Tadorninae)
Tribe : Plectopterini
Genre : Mute geese ( Sarkidiornis )
Type : Mute goose
Scientific name
Sarkidiornis melanotos
( Pennant , 1769)

The humped goose ( Sarkidiornis melanotos ), sometimes also referred to as the glossy duck , is the only species in the genus of the humped goose and belongs to the family of ducks .

The grouping in the tribe Plectropterini, in which the humped goose is placed together with the spur goose , was based on similarities in behavior. In addition, there are significant differences in size between the sexes in both species.

Appearance

Mute geese have white plumage on the neck, head and chest. The body surface is glossy blue-black. The males also have a conspicuous beak on their black and white speckled head, which, however, regresses in animals that are inactive in reproduction. The flanks of the male are pinnate gray or black depending on the subspecies.

The chick's downy dress is olive green on the top while it is yellow on the face, chest and underside.

Subspecies

Distribution map of the Old World Mute Goose

There are two subspecies:

  • the old world humpback goose ( S. m. melanotos ), in which the male has light gray flanks
  • the New World humped goose ( S. m. sylvicola ) with deep black flanks in the males

A clear assignment of the females to these subspecies is not possible in contrast to the males. The females of both subspecies look identical. In ornamental poultry keeping, the two subspecies are mostly mixed because both subspecies were imported.

Occurrence, habitat and stock

Females of the New World subspecies
Female Mute Goose

Mute geese are not endangered bird species. The subspecies of the Altwelt-Höckerglanzganz occurs in Africa and southeast Asia. It is most commonly found in the delta of the Senegal and Niger rivers . Outside of the breeding season, up to 40,000 animals of this species can be observed there. Their habitat in Africa are swamp and river plains as well as flood plains. It is often jointly with spores geese , Pfeifgänsen and Nilgänsen observed. In Asia it is also often found on rice fields.

The New World Mute Goose, which is native to South America, is rarer. In some regions of Venezuela and Argentina , it is heavily hunted, causing its populations to decline.

According to the IUCN , the total population of the species is 190,000 to 730,000 animals. The humped goose is considered "not endangered".

food

Mute geese feed mainly on marsh and aquatic plants. They can cause great damage to game on rice fields and are also often hunted for this reason.

Reproduction

Mute geese belong to the polygamous duck birds . As a rule, a ganter consists of three to four females. Humpback geese display a distinctive courtship ritual in which the females are also heavily involved. They often circle around the ganter, which usually reacts with deep bows of the head and neck.

The nests are built near the water in the bushes or in the swamp vegetation. However, they also use tree hollows and up to three females lay the eggs in a nest. The eggs are only incubated by the females, and a single bird can lay up to 8 to 12 shiny creamy white eggs. The chicks hatch after 30 days of incubation.

Attitude in Europe

Mute geese are not shown very often in zoos or kept by private individuals as aquatic fowl because they are considered temperature-sensitive. The nominate form was first bred in England in 1931. The South American subspecies was also kept in France in the 1930s.

Individual references, literature and web links

Individual evidence

  1. ↑ Kolbe, p. 135.

literature

Web links

Commons : Humped goose ( Sarkidiornis melanotos )  - Collection of images, videos and audio files