A collaboration between the Matukituki Charitable Trust, Ngāi Tahu, Department of Conservation Mohua Recovery Group, Mohua Charitable Trust, and Southern Lakes Sanctuary saw the translocation through last week.

This involved the safe capture of mohua on Pukenui (Anchor Island), Fiordland, followed by transfer and release at a site up-valley from Aspiring Hut. This timing allows the birds to settle before the breeding season.

The West Matukituki Valley, in Mt Aspiring National Park has been the focus of sustained predator control by the Matukituki Charitable Trust over the past decade.

That work, supported by DOC and Southern Lakes Sanctuary, has helped reduce predator numbers to a level where the reintroduction of threatened species is possible.

Trustees of the Matukituki Charitable Trust first identified mohua reintroduction as a long-term goal about eight years ago. The valley's silver beech forest, relative isolation, and the progress of predator management made it a suitable site for establishing a new mohua population.

"To now see that happening is hugely rewarding for everyone who has supported the project and a positive step for biodiversity in the valley," Mrs Crombie said.

Predator management in the valley has provided benefits for a wide range of native species, including toutouwai (South Island robin), kākāriki, tītitipounamu (rifleman), South Island kākā, kea, pīwauwau (rock wren), braided riverbed birds such as tarapirohe (black-fronted tern) and pohowera (banded dotterel), as well as bats, lizards and native mistletoe.

The addition of mohua marks a further step toward the long-term conservation objective of restoring native species in both the West and East Matukituki Valleys and adjoining catchments, with the support of local landowners.

Paul Kavanagh, Chief Executive of Southern Lakes Sanctuary, said the reintroduction reflects the collective effort of many organisations and individuals over a long period of time.

"Bringing mohua back to the Matukituki is a really special moment ... The years of predator control and planning are paying off, and seeing these birds back in the valley is a milestone for everyone involved."

Mohua were once widespread and common across New Zealand forests but are now confined to small, scattered populations in the South Island, with fewer than 5000 birds remaining.