 C. f. xanthanotus , known as the southern yellow @-@ tailed black cockatoo , is found in western Victoria , southeastern South Australia , the islands of Bass Strait , and Tasmania . Gould described it in 1838 and later changed his spelling to " <unk> " . However , the first name was recognised as taking precedence under ICZN naming rules and its spelling preserved . Saunders reported in 1979 that male birds from Tasmania had wider bills than their mainland relatives , and that Tasmanian female birds were larger than males . However , this observation has yet to be replicated and most authorities only recognize two subspecies . If a third subspecies is recognized , the southern mainland subspecies would be named <unk> , having been named so by Gregory Mathews in 1912 , and the name xanthanotus , originally applied to a Tasmanian specimen , would be restricted to the Tasmanian population . 
