The world's rarest kiwi species is making a return to the North Island after a 100-year absence.
Twenty young rowi are being released on predator-free Mana Island, off the Kapiti Coast, on Tuesday in the hope they will breed.
As part of what's been named Operation Nest Egg, the Department of Conservation removed 20 rowi eggs from the Okarito forest in South Westland.
The eggs were hatched at the West Coast Wildlife Centre in Franz Josef and the chicks raised to maturity on predator-free Motuara Island in the Marlborough Sounds.
The work of Operation Nest Egg has meant rowi numbers have doubled to 400 over the past five years.
The Department of Conservation says the project may set a trend in the way they help other kiwi species that are also under threat.