The future of a rare species of Kiwi could rest on three pairs moved to a new home in the Marlborough Sounds.
Conservationists are counting on favourable new surroundings boosting the fertility of three kiwi couples.
Three pairs of the rarest kiwi, rowi kiwi from the West Coast, were released on to predator-free Blumine Island in Queen Charlotte Sound yesterday.
The species has about 350 birds, mostly in a sanctuary at South Okarito Forest.
Department of Conservation rowi team leader Duncan Kay said the future of the species could rest on the fertility of the birds released yesterday.
"We hope the better conditions on Blumine Island will contribute to the breeding success of these birds," said Mr Kay.
The warmer climate on the island and the food-rich soils should contribute to breeding success, he said.
Jim Livingstone, the department's Franz Josef biodiversity programme manager and head of the rowi recovery project, said the kiwi had to compete for food in Okarito.
Their area on the coast was also small and not predator-free.
"Going to Blumine will be like paradise and may encourage them to breed."
The birds were very special, he said. "They could be older than anyone here; we don't know their exact ages.
"They are pairs and they mate for life.
"Hopefully, the conditions on Blumine will suit them."
It was the first time kiwi pairs had been taken out of their natural environment to stimulate fertility.
Any offspring from the population that establishes on the 400-hectare island will be returned to Okarito to spread their genes.
Mr Kay said some of the pairs had been with their partners for many years, and their lack of breeding success was puzzling.
West Coast iwi Makaawhio and Marlborough iwi Te Atiawa welcomed the birds and signed an agreement at Waikawa Marae yesterday morning for the ongoing wellbeing of the kiwi in their new home.
Representatives of both iwi blessed the kiwi before they were released at three locations on Blumine Island.
Conservation staff have separate plans to move another dozen birds, kept on the predator-free Motuara Island in Queen Charlotte Sound, to Mana Island near Kapiti, and eventually release their offspring into North Okarito Forest.
The kiwis' relocation to Blumine Island has been a joint effort between the department's Franz Josef and Picton offices, Makaawhio and Te Atiawa iwi, BNZ Save the Kiwi Trust and Untouched World.
- The Marlborough Express