A bird once thought to be extinct for 150 years is now reportedly breeding on islands in Auckland's Hauraki Gulf, according to evidence collected this week.
The New Zealand storm petrel was rediscovered by birdwatchers in 2003, near the Mercury Islands, east of the Coromandel.
This week, four out of five birds collected in a research mission showed signs of "brood patches" on their belly used to incubate eggs.
Researchers from the University of Auckland and DOC began their mission before dawn on Wednesday, using net guns to capture the birds.
DOC seabird expert Graeme Taylor says the presence of brood patches "strongly suggests" they are breeding.
He says islands in the Hauraki Gulf are the most likely sites.
The tiny bird had been considered extinct for 150 years, meaning its comeback eclipses those of other "extinct" birds like the Takehe and Chatham Islands taiko.
There had been much speculation about whether the petrel breeds on one of the gulf's many islands or is just a visitor to New Zealand.
This week's discovery has important implications for funding because DOC provides more money to species whose breeding location and population numbers are known.
The research team will continue its capture programme through February and March to find out more about the birds' breeding cycle.
Once additional funding is secured researchers will begin tracking the birds with radio devices.
Mayor John Tregidga, Chairman of the Hauraki Gulf Forum, welcomed the finding.
"It's wonderful to think that these birds are breeding right now on islands in the outer Hauraki Gulf, quite possibly in sight of where the researchers captured them."
New Zealand storm petrels are considered critically endangered and finding where they breed is important to help conservation efforts.
- Auckland Now
Is there enough support for new migrants once they arrive in New Zealand?