New Zealand's wētāpunga — a flightless insect heavy enough to outweigh a mouse — just hit a conservation milestone almost no invertebrate on Earth reaches: four confirmed generations born and surviving in the wild, on islands where it hadn't existed for centuries.

  • 11,000+ wētāpunga released into the wild since the programme began
  • 15 years of captive breeding behind the recovery
  • 10 release sites across predator-free islands and mainland sanctuaries
  • 4 wild generations now confirmed — the internationally recognized benchmark for an established population

From one last island to ten new ones

As early European settlers cleared land for farms and introduced rats and stoats, wētāpunga vanished from every wild refuge except Te Hauturu-o-Toi/Little Barrier Island. Surveys between 2005 and 2009 found too few wild individuals left to supply new populations directly, so conservationists collected a small founding group instead.

Breeding began at Butterfly Creek, a wildlife park, producing enough insects for the first island releases on Motuora and Tiritiri Matangi in 2010 and 2011. Auckland Zoo established a second breeding colony in 2012 and scaled up the process, raising young wētāpunga together in communal nurseries on a diet of fresh foliage, fish-flake protein and leaf litter. Between 2014 and 2025, the zoo alone bred and released 8,874 of the insects.

Altogether, the programme's 45 separate transfers carried wētāpunga to eight predator-free islands and, more recently, two fenced mainland sanctuaries north of Auckland.

A benchmark most endangered species never reach

Monitoring on Motuora and Tiritiri Matangi has now recorded at least four generations of wētāpunga born on the islands themselves — internationally recognized as confirmation that a released population has successfully established itself. Several of the programme's other island populations are progressing toward the same milestone.

The species' official conservation status has improved accordingly, from "Threatened – Nationally Endangered" in 2004, before the breeding programme began, to "Threatened – Nationally Increasing" in 2022.

"The expertise, commitment, and collaboration of many people and organizations contributed to the recovery of this iconic giant wētā." — Dr. Chris Green, Department of Conservation, lead author of the recovery study

A model for other endangered insects

Ngāti Manuhiri, the customary guardians of Te Hauturu-o-Toi/Little Barrier Island, provided ongoing support as kaitiaki throughout the programme, since wētāpunga are a taonga — a treasured species — for the iwi. Community restoration groups across the upper North Island also helped fund the intensive management the insects required and organized the releases.

Green and his co-authors documented the full recovery in the New Zealand Journal of Zoology, in what he calls one of the most comprehensive case studies of invertebrate conservation breeding ever undertaken anywhere. The techniques are already informing a new breeding effort for the Māhoenui giant wētā at the Ōtorohanga Kiwi House, and researchers hope the same approach could help other critically endangered invertebrates, including the Canterbury knobbled weevil.

Once confined to a single island, wētāpunga are now reproducing on multiple refuges — giving a species many had written off more than one home to call its own.