New Zealand colonised 1000 years later than previously thought

Trevor Worthy is part of an international team of four researchers who have used radiocarbon dating of Pacific rat bones and rat-gnawed native seeds to show that humans arrived on New Zealand about 1280-1300AD, not 200BC as previously thought.

The controversial finding has been published today in the prestigious journal Proceedings of the National Academy of Sciences in the United States.

Mr Worthy, from the School of Earth and Environmental Sciences, said the carbon dating results do not support previous claims published in Nature in 1996 that humans visited the country over 2000 years ago.

“”There is no supporting ecological or archaeological evidence for the presence of Pacific rat or humans until 1280-1300AD and the reliability of the bone dating from that first study has been questioned,” he said.

This is the first time that the actual sites involved in the original study have been re-excavated and analysed.

Team leader Dr Janet Wilmshurst from Landcare Research in New Zealand said the dating of the rat bones is consistent with other evidence from the oldest dated archaeological sites in the country.

“As the Pacific rat or kiore cannot swim very far, it can only have arrived in New Zealand with people on board their canoes, either as cargo or stowaways. Therefore, the earliest evidence of the Pacific rat in New Zealand must indicate the arrival of people,” Dr Wilmshurst said.

The dating of the rat bones is also supported by the dating of more than 100 woody seeds, many of which have distinctive tell-tale rat bite marks, preserved in peat and swamp sites from the North and South Islands.

The finding suggests that colonisation of New Zealand did not involve a protracted delay between initial discovery and subsequent colonisation, an idea implicit in earlier theories.

“The first people arriving in New Zealand from tropical east Polynesia initiated an immediate and rapid transformation,” Dr Wilmshurst said.

Mr Worthy, a world bird expert, joined the University of Adelaide from New Zealand in 2005. He has just completed his PhD on fossil waterfowl of Australia and New Zealand.

Source: The University of Adelaide