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
Branta material and comparisms with other subfossil bones assigned to the genus "Branta" it was redescribed as "Branta rhuax" in 2013. It was another prehistoric Big Island form and remains known only from some parts of a single bird's skeleton, which were much damaged because the bird apparently died in a volcanic eruption, with the bones being found in an ash-filled depression under a lava flow. A presumed relation to the shelducks proposed by Lester Short in 1970 was generally considered highly unlikely due to that group's biogeography, but more recently, bones of a shelduck-like bird have been found on Kaua‘i.