10 Jul 2018

Ancestor's dinners gives new insight into NZ biodiversity

9:52 pm on 10 July 2018

Scientists have been examining the eating habits of our ancestors to study the impact early humans have had on New Zealand's biodiversity.

Excavation site at Awamoa

Excavation site at Awamoa Photo: Shar Briden, Absolute Archaeology Limited, Dunedin

They've been looking at fossil fragments from 20,000 years ago and comparing them with our ancestors' food scraps from about 750 years ago.

The study was led by Curtin University in Perth with the help of New Zealand researchers and institutions such as University of Otago, Canterbury Museum and Museum of Te Papa Tongarewa.

New Zealand was the last major landmass to be settled by humans, which means researchers can look at the relationship between the fauna and its first contact with people in high detail.

They say they've discovered 100 different species, 14 of which are now extinct.

Among their discoveries were nine lost kākāpō lineages from both the North and South Island and dolphin DNA, which was found near what appeared to be bone harpoon hooks.

University of Otago's Department of Zoology's Dr Nic Rawlence said the research had given them new insights into early polynesian life.

Unidentifiable bone fragments from Wairau Bar

Unidentifiable bone fragments from Wairau Bar Photo: Professor Michael Bunce, Curtin University

"What we're finding is that sealions and southern elephant seals, which were breeding in New Zealand when Polynesians arrived, were just as important in Māori diet as fur seals, which we didn't know before," he said.

Dr Rawlence said we now know early Māori also liked to fish locally and, like europeans, had an impact on wiping out kākāpō lineages.

"When Polynesians arrived in New Zealand, there were 10 lineages of kākāpō and we're now left with one, across the entirety of the population, so you've got a situation much like the English Royal Family, where there is very little genetic variation," he said.

The knowledge obtained through the research will help current conservation efforts, he said.

"There's a famous phrase that the past is the key to the present and the future, so by doing what we call this bone grab technique on the fragments, we've been able to create a more nuanced picture of what New Zealand was like and we've now been able to use this information to do smart restoration of what we have left," he said.