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
Canada goose which contains species with largely black plumage, distinguishing them from the grey species of the genus "Anser". "Branta" is a Latinised form of Old Norse "Brandgás", "burnt (black) goose" and the specific epithet "canadensis" is a New Latin word meaning "from Canada". According to the "Oxford English Dictionary", the first citation for the 'Canada goose' dates back to 1772. The Canada goose is also colloquially referred to as the "Canadian goose". The cackling goose was originally considered to be the same species or a subspecies of the Canada goose, but in July 2004, the American Ornithologists' Union's Committee on Classification