Curator of vertebrates, Alan Tennyson, discusses new findings published today that New Zealand and the Chatham Islands had their own unique prehistoric swan. 

Black swans (Cygnus atratus) are a common and prominent part of New Zealand’s wetland fauna today – but have they always been here, or are they recent invaders?

For many decades it has been unclear whether or not New Zealand once had its own unique species of swan.

Back in 1890, the Canterbury Museum’s Director, Henry Ogg Forbes, described a prehistoric New Zealand swan (Cygnus sumnerensis) based on fossil bones, but by 1998 this was considered to be the same species as the living black swan found in New Zealand and Australia today.

However our new study, led by Otago University researchers, on ancient swan DNA from museum bones has now shown that Forbes was correct. New Zealand did have a prehistorically extinct swan and the Chatham Islands had another closely related form, also extinct. Their extinction occurred about AD 1450, quite soon after humans arrived in the late 13th century and was evidently due to over-hunting.

Today’s black swans arrived in New Zealand through human introduction and probably also under their own steam from Australia at a similar time in the mid-1800s.

The extinct swans were considerably larger than black swans, with relatively shorter wings and longer legs.

The extinction of New Zealand’s endemic swans adds yet another species to the long list of extinct birds from New Zealand.

Read the full research paper in Proceedings of the Royal Society B. Biological Sciences

Ancient DNA and morphometric analysis reveal extinction and replacement of New Zealand’s unique black swans by Nicolas J. Rawlence, Afroditi Kardamaki, Luke J. Easton, Alan J. D. Tennyson, R. Paul Scofield, Jonathan M. Waters