After travelling by boat, plane, van and helicopter, nearly 50 white-faced storm petrels have arrived on Mana Island from Rangatira Island.
“I’m absolutely chuffed, I’ve spent the last month worrying about the weather!” Friends of Mana Island President John McKoy said.
The journey from the Chatham Islands to the predator-free Mana Island off the coast of Porirua is a distance of nearly 800km.
Department of Conservation principal science advisor Graeme Taylor said it’s the first attempt in New Zealand to transfer storm petrels from island to island, and most likely in the world.
“We’re very supportive of this project, it’s part of the restoration of Mana Island, getting sea birds back here breeding,” he said.
Mr Taylor said it’s believed the white-faced storm petrel Cook Strait colony was based on Mana Island, before people first inhabited the island more than a thousand years ago.
FOMI President John McKoy said the mission is the pilot attempt for future translocations of the species, with an aim to relocate 250 chicks from Rangatira Island over the next three years.
“It’s all about our cunning plan to get the island back to something like the original Cook Strait ecosystems,” he said.
“The more sea birds we have on the island the better over time because they bring nutrients on to the land.”
Seabirds already on the island unintentionally create homes for tuatara and insects when they make burrows.
When they breed on land, nutrients from the food they eat at sea boosts the soil and survival of other animals when they poo, regurgitate food, and through egg shells.
Bringing the chicks to Mana Island has taken several years of discussions with Hokotehi Moriori and Ngati Mutunga [Chatham Islands], Ngati Toa [Mana Island] and Department of Conservation, as well as sorting out the logistics of the transfer.
Biologist Cathy Mitchell hand-selected the chicks from Rangatira Island based on their age and weight, the ideal size being 45 grams.
“They’re very delicate little birds, particularly delicate as far as sea birds go,” Mr McKoy said.
The six- to seven-week-old chicks will be fed sardine smoothies and given a check-up on the island by rostered FOMI volunteers for up to 15 days.
When the birds are thought to be big enough to emerge in around a week, the gates on their man-made burrows will be opened, giving them the choice to leave the island, for life at sea for several years, when they are ready.
“We estimate that about 60 per cent of the birds that fledge from Mana Island will survive their first year at sea,” DOC principal science advisor Graeme Taylor said.
Mr Taylor said based on the translocation of other sea birds to Mana Island, it’s estimated 10 to 40 per cent of the total 250 birds will return to breed.
Others will return to Rangatira Island, or another predator-free island, he said.
At least 10, but ideally 20, breeding pairs are needed for the aim of establishing a breeding colony on Mana Island to be successful.