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
Egyptian goose 100 sightings just in 1Q 2018 as reported in ebird.org database. The Egyptian goose is believed to be most closely related to the shelducks (genus "Tadorna") and their relatives, and is placed with them in the subfamily Tadorninae. It is the only extant member of the genus "Alopochen", which also contains closely related prehistoric and recently extinct species. mtDNA cytochrome "b" sequence data suggest that the relationships of "Alopochen" to "Tadorna" need further investigation. The generic name is based on Greek ἀλώπηξ ("alōpēx"), "fox", and χήν ("chēn") "goose", referring to the ruddy colour of its back. The species name "aegyptius"