The success of a large-scale recovery programme for wētāpunga/Little Barrier giant wētā, New Zealand’s heaviest insect, has been officially documented in the New Zealand Journal of Zoology.
Over 15 years, tens of thousands of wētāpunga were bred at Butterfly Creek and Auckland Zoo enabling 45 translocations of 11,000 wētā to 10 new wild sites. As a result, the species’ conservation status has improved from Threatened – Nationally Endangered (2004) before the programme started to Threatened – Nationally Increasing (2022).
Lead author Dr. Chris Green, Honorary Research Associate of Department of Conservation, says it’s vital to document the scientific knowledge gained from the wētāpunga recovery efforts.
“The journal paper summarises one of the most comprehensive case studies of invertebrate conservation breeding, translocation and species recovery ever undertaken in Aotearoa New Zealand, perhaps the world. My co-authors have contributed significant expertise gained from years of hands-on experience working with wētāpunga.
“By documenting this amazing conservation success story, we can share valuable knowledge on husbandry, release methods, and population persistence.
“The expertise, commitment and collaboration of many people and organisations contributed to the recovery of this iconic giant wētā.”
Ngāti Manuhiri, kaitiaki of wētāpunga and mana whenua of Te Hauturu-o-Toi/Little Barrier Island, where the founding wētāpunga originate, provided ongoing support and engagement in the programme. Wētāpunga are taonga species for Ngāti Manuhiri.
Butterfly Creek established early husbandry and release techniques which Auckland Zoo subsequently refined and ‘industrialised’ to rear huge numbers of zoo-bred wētā in communal creches. This greatly increased the number of animals for release and enabled the expansion of the programme to multiple predator-free islands in the Hauraki Gulf and Bay of Islands, and most recently, mainland reserves, north of Auckland.
Community restoration groups across the upper North Island were critical to the programme, raising finances to support the resource-hungry intensive management of the wētā as well as helping to organise and support releases and ongoing monitoring.
“The future of wētāpunga is looking bright. What we have learnt is now informing breeding of Māhoenui giant wētā at the Ōtorohanga Kiwi House. There are many more critically endangered invertebrates that could benefit from similar programmes, for example the Canterbury knobbled weevil (Hadramphus tuberculatus) and several native stag beetle species,” says Chris.
Read the paper here: Captive Breeding Programme Enables a Successful Wētāpunga (Deinacrida heteracantha: Orthoptera: Anostostomatidae) Recovery Programme.
Background information
Wētāpunga (Deinacrida heteracantha) is the largest species of Aotearoa New Zealand’s giant wētā and the heaviest orthopteran in world.
Early European settlers cleared the land for farming and destroyed wētāpunga habitat, and introduced rats, stoats and other pests which resulted in the dramatic decline and extinction of all wētāpunga populations except on Te Hauturu-o-Toi.
In the 1990s a DOC Threatened Wētā Recovery Plan recognised wētāpunga as one of New Zealand’s most threatened species and urgent action was required.
Surveys on Te Hauturu-o-Toi/Little Barrier Island between 2005-2009 indicated this remnant population was too small to facilitate direct translocations to set up new populations, leading to the establishment of the ex situ conservation breeding programme.
Initially a small number of wētā were collected from Te Hauturu-o-Toi/Little Barrier Island to initiate a breeding colony at Butterfly Creek. After successfully transferring the animals and establishing husbandry parameters, that founding colony produced the first wētāpunga for release onto two Hauraki Gulf/Tīkapa Moana islands, Motuora and Tiritiri Matangi in 2010 and 2011.
In 2012 Auckland Zoo set up a second breeding colony, greatly expanding the programme and refining husbandry to increase productivity – to a scale that from 2014 to 2025 saw it breed and release 8,874 wētāpunga. By 2025, more than 11,000 wētāpunga had been raised at Auckland Zoo and Butterfly Creek and released onto eight predator-free islands in the Hauraki Gulf and Bay of Islands and most recently, two mainland fenced sanctuaries.
Intensive monitoring on Motuora and Tiritiri Matangi islands shows at least four generations of wētāpunga have been born there. Internationally this is recognised as confirmation that this giant wētā has successfully established on both islands. Many of the other island populations are also well on their way to reaching this milestone.
