Barnacle goose were of the same nature as other birds. The question of the nature of barnacle geese also came up as a matter of Jewish dietary law in the Halakha, and Rabbeinu Tam (1100–71) determined that they were kosher (even if born of trees) and should be slaughtered following the normal prescriptions for birds. The mythical barnacle tree, believed in the Middle Ages to have barnacles that opened to reveal geese, may have a similar origin to the other legends already mentioned. Barnacle goose The barnacle goose ("Branta leucopsis") belongs to the genus "Branta" of black geese, which contains species with
Red-breasted goose Red-breasted goose The red-breasted goose ("Branta ruficollis") is a brightly marked species of goose in the genus "Branta" from Eurasia. It is sometimes separated in "Rufibrenta" but appears close enough to the brant goose ("Branta bernicla") to make this unnecessary, despite its distinct appearance. It is currently classified as vulnerable by the IUCN. "Branta" is a Latinised form of Old Norse "Brandgás", "burnt (black) goose and "ruficollis" is from the Latin "rufus" "red" and "collis" "necked". All the species of the genus "Branta" are distinguished by their dark sooty colour, relieved by white, and as a distinction from the grey