Concept

Branta

Résumé

The black geese of the genus Branta are waterfowl belonging to the true geese and swans subfamily Anserinae. They occur in the northern coastal regions of the Palearctic and all over North America, migrating to more southernly coasts in winter, and as resident birds in the Hawaiian Islands. Alone in the Southern Hemisphere, a self-sustaining feral population derived from introduced Canada geese is also found in New Zealand. The black geese derive their vernacular name for the prominent areas of black coloration found in all species. They can be distinguished from all other true geese by their legs and feet, which are black or very dark grey. Furthermore, they have black bills and large areas of black on the head and neck, with white (ochre in one species) markings that can be used to tell apart most species. As with most geese, their undertail and uppertail coverts are white. They are also on average smaller than other geese, though some very large taxa are known, which rival the swan goose and the black-necked swan in size. The Eurasian species of black geese have a more coastal distribution compared to the grey geese (genus Anser) which share the same general area of occurrence, not being found far inland even in winter (except for occasional stray birds or individuals escaped from captivity). This does not hold true for the American and Pacific species, in whose ranges grey geese are, for the most part, absent. The genus Branta was introduced by the Austrian naturalist Giovanni Antonio Scopoli in 1769. The name is a Latinised form of Old Norse Brandgás meaning burnt as in "burnt (black) goose". The type species is the brant goose (Branta bernicla). Ottenburghs and colleagues published a study in 2016 that established the phylogenetic relationships between the species. The genus contains six living species. Two species have been described from subfossil remains found in the Hawaiian Islands, where they became extinct in prehistoric times: Nēnē-nui or wood-walking goose, Branta hylobadistes (prehistoric) Similar but hitherto undescribed remains are known from on Kauaʻi and Oʻahu.

Source officielle

https://fr.wikipedia.org/wiki/Branta

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