The largest specimens of extinct birds are said to have been found mostly on islands. Thus, not surprisingly a giant swan fossil was discovered 500 miles east of New Zealand on the Chatham Islands. This great swan fossil, first classified as Cygnus sumnerensis, survived into the sixteenth or seventeenth century. A more complete fossil of this swan, possibly the ancestor of Australia’s present-day Black Swan, has been reclassified as Cygnus chathamnensis to designate more precisely the islands where the fossil was found.
It is believed that the discovery of the bones on the islands was made by accident when E.O. Forbes, the discoverer, first heard the New Zealand Maori speak of the “Pouwa” bird and how they drove them from the Te Whanga lagoon.