A new species of bird native to New Zealand has been discovered living on a 1km strip of sand on Whenua Hou (Codfish Island), off the coast of Stewart Island.

The birds have been named the Whenua Hou diving petrel (Pelecanoides whenuahouensis) and the population is believed to be only around 250.

They were found as a result of a joint research project between Victoria University of Wellington, the Department of Conservation (DoC), the Museum of New Zealand Te Papa Tongarewa and the Chizé Centre for Biological Studies in France.

Doctoral candidate Johannes Fischer worked on the project and said researchers compared the birds with museum specimens from all over the world to look for differences.

"Until now, it was assumed this was a population of South Georgian diving petrels. However, we discovered differences in the birds' size, shape and colour," he said.

"They're also the only diving petrel known to breed entirely within a sand dune environment. Together, these differences are enough to identify them as a separate species based on the IUCN Red List of Threatened Species criteria."

Mr Fischer worked with Kaitiaki Roopu, a group made up of representatives from Southland's four Ngāi Tahu rūnanga to name the species.

Now he's working with DOC seabird researchers Dr Igor Debski and Graeme Taylor on a conservation plan for the tiny population of birds.

Without any predators around, the main danger for the birds is the loss of their natural habitat of sand dunes to climate change.

Scientists are still working out the details, but they haven't ruled out moving the petrels.

"As we gain more detailed knowledge of the species over time, we can look to more proactive management, including translocations to suitable places to help the species thrive," Mr Taylor said.

Newshub.