Five pairs have each successfully raised a juvenile bird on the Hauraki Gulf island, which is a sanctuary site for the threatened bird.
Thought to be extinct, the birds were rediscovered in 1948 by Southland doctor Geoffrey Orbell in the Murchison Mountains in Fiordland.
On Tuesday, the five juveniles were officially counted in the total national population of the species of just over 500 birds.
Takahē breed only once a year, raising one to two chicks. These five hatched in November-December last year.
Department of Conservation (Doc) and Ngāi Tai ki Tāmaki said in a statement they played active roles on pest-free Motutapu, staff regularly observing the birds and undertaking a range of conservation work to support takahē and other native species.
"Years of work by many different people on Motutapu, from intensive biosecurity and pest responses, to planting native species, observing and health management, support the takahē to live and breed in a stable environment," Doc Hauraki Gulf inner islands operations manager Kat Lane said.
Auckland Zoo staff bring their specialised skills to the field, supporting the takahē population on the island with regular health checks, veterinary support and banding and sexing the juveniles, as part of their mahi for the wider North Island meta-population.
Motutapu is the largest of New Zealand’s 17 sanctuary sites in terms of land area and takahē population. It is home to 28 takahē including these juveniles, who will remain on island and join the breeding population as they mature.
"You can see the takahē during a trip to Motutapu — they’re often spotted around the causeway between the two islands or at Home Bay. We ask the public to keep a good distance away and not feed them."
Doc takahē recovery programme senior ranger Glen Greaves said the local success was heartening news.
"After a decade of ups and downs, it’s fantastic to see the takahē population on Motutapu flourishing. Five juveniles being raised from five breeding pairs, along with several years of good adult survival, is comparable with the top tier of takahē sanctuary sites and bodes well for the future.
"We think fewer transfers of takahē to Motutapu has resulted in better population stability, and habitat restoration through years of planting is likely having a positive impact on bird health."
Motutapu has plenty of grasses and sedges for the birds to feed on and areas of native bush provide edge habitat while supporting the overall ground moisture.
Mr Greaves said Doc would be working closely with Ngāi Tahu in the South Island and Ngāi Tai ki Tāmaki as kaitiaki for Te Motutapu a Taikehu to make the most of the success and align local strategy with wider recovery goals.
"The overarching goal for the Takahē Recovery Programme is to create multiple self-sustaining wild populations, within the historic range of the species."
