The analysis of a moa skeleton on Rakiura Stewart Island shows the birds may have lived there at the same time as humans.
Research from the University of Otago and the Department of Conservation was undertaken after the discovery of the bird's skeleton on Rakiura's West Ruggedy Beach last March by DOC ranger Phred Dobbins.
Analysis showed the bird was a South Island giant moa that died around 700 years ago, between 1297-1395 just after the arrival of Polynesians on the island.
The findings published in the New Zealand Journal of Ecology add to a long-running debate regarding whether moa were indigenous to Rakiura, as few natural moa remains have been found on the island.
Lead author Dr Alex Verry said the excavation revealed a partial moa skeleton, with no cut marks from stone tools.
Gizzard stones were also unearthed, above a dark organic-rich layer of sand beneath the skeleton that was likely stained by the rotting moa and the plant contents of its gizzard.
The skeleton was found 500m inland from the coast, in an eroded depression inside a granite boulder after storm events stripped the dune system to its granite base, exposing the remains.
The director of the Otago Palaeogenetics Laboratory and research paper co-author, Dr Nic Rawlence, said ancient DNA analysis revealed the skeleton belonged to a South Island giant moa while radiocarbon dating showed it died around 700 years ago, just after the arrival of Polynesians on the island.
"The findings suggested the South Island giant moa had died near to where it was found and represented a moa that naturally occurred on Rakiura and died a natural death.
"We believe it is likely to be of natural origin, despite its post-human date."
The research team excavated the skeleton with the assistance of Dr Matt Schmidt, senior heritage adviser from the Department of Conservation, in close consultation with Murihiku Ngāi Tahu, kaitiaki and mana whenua of Rakiura.
Schmidt said the discovery that this species of moa was alive when Māori first occupied Rakiura significantly added to the cultural narrative of the island.
He said this sort of research was invaluable for understanding the island's past and informing its future management.
"A large amount of important contextual information is lost when individuals take it upon themselves to remove moa remains from protected areas like national parks and archaeological sites, in order to sell them.
"Without this appropriate contextual data, these remains become near scientifically useless," Schmidt said.
The research highlighted the importance of scientists working with iwi, particularly given moves to stop the removal of moa bones from archaeological and fossil sites to sell online.
The government and Department of Conservation are now considering banning the sale of subfossil bird bones, including moa, in New Zealand.