Brant (goose) the "Agreement on the Conservation of African-Eurasian Migratory Waterbirds" applies. "Branta" is a Latinised form of Old Norse "brandgás", "burnt (black) goose", and "bernicla" is the medieval Latin name for the barnacle. The brant and the similar barnacle goose were previously considered one species, formerly believed to be the same creature as the crustacean. That myth can be dated back to at least the 12th century. Gerald of Wales claimed to have seen these birds hanging down from pieces of timber, William Turner accepted the theory, and John Gerard claimed to have seen the birds emerging from their shells. The
Canada goose the cackling goose, which slightly overlap in mass. However, most subspecies of the cackling goose (exclusive of Richardson's cackling goose, "B. h. hutchinsii") are considerably smaller. The smallest cackling goose, "B. h. minima", is scarcely larger than a mallard. In addition to the size difference, cackling geese also have a shorter neck and smaller bill, which can be useful when small Canada geese comingle with relatively large cackling geese. Of the "true geese" (i.e. the genera "Anser", "Branta" or "Chen"), the Canada goose is on average the largest living species, although some other species that are geese in name, if