In other species: Coscoroba swan , black swan , rock pigeon , helmeted guineafowl , chicken , Arctic skua , pomarine skua , brown booby , red-footed booby , zebra finch , Lesser snow goose , Bananaquit , gyrfalcon , ruff , , Eleonora's falcon

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 266300 (trait) , 155555 (gene)

Mendelian trait/disorder: unknown

Considered a defect: no