Auckland Zoo and Motuihe Trust team up to help rare forest giant

Auckland Zoo and the Motuihe Trust are working together to return one of the world’s heaviest and most spectacular insects, Aotearoa’s unique giant wētā the wētāpunga, to Te Motu-a-Ihenga (Motuihe Island) in Auckland’s Hauraki Gulf.

While the Covid-19 lockdown prevented a group gathering for an earlier release in March, a few days ago the Trust, Zoo, iwi and Department of Conservation (DOC) were delighted to come together to see and celebrate the release of an additional cohort of wētāpunga onto the island – that it’s hoped in a few years’ time will become home to a self-sustaining population.

A three-year partnership between Auckland Zoo and Motuihe Trust with the support of iwi Ngāi Tai ki Tamaki, Ngāti Paoa, Marutūahu, Ngāti Rehua and Ngāti Manuhiri, and DOC is part of a wider recovery programme to secure the long-term future for this threatened endemic taonga - once widespread throughout Auckland and Northland and their islands, including Great Barrier, but now only naturally found on Hauturu-o-Toi (Little Barrier).

“Thanks to the great support of iwi, DOC, and The Noises’ guardians the Neureuter family, Auckland Zoo has led the breeding and release of more than 5000 wētāpunga onto pest-free Hauraki Gulf islands since 2012. From releases onto Motuora, Tiritiri Matangi, and the Noises’ Otata and Motuhoropapa islands, we are seeing the welcome results of second generations of these gentle giants flourishing on these islands,” says Auckland Zoo Ectotherms team leader, Don McFarlane.

“Wētāpunga are among our planet’s most amazing creatures, but like so many bugs, are often under-rated. These giant herbivorous gardeners of the forest play a vital role in restoring and maintaining the health of ecosystems, and in turn species recovery, so it’s fantastic to now have Motuihe become a fifth island haven for them. With breeding success already across four islands, and now with the addition of Motuihe, it’s likely that down the track more islands could receive wētāpunga via wild-to-wild translocations to further safeguard their future,” says Don.   

Motuihe Trust chairman John Laurence says its volunteers are “super excited that a very ancient and rare insect will now be living in forests restored by tens of thousands of children and adults over the last 20 years”. “Volunteers treat this release of such a wonderful and iconic animal as a reward for their work in planting 450,000 trees, weed control, walking track formation, and conservation advocacy. Wētāpunga will be watched and studied with exhilaration and amazement by students and visitors, and adds to the already flourishing populations of kiwi, tuatara, bellbird, saddleback, kākāriki, whitehead, skinks, and geckos which have been previously released on Motuihe Island."

DOC Technical Advisor Chris Green says, “Due to animal pests, and the destruction of native forests, wētāpunga have been wiped out on the mainland”.

“Since 2010, wētāpunga have been released on pest free islands on the Hauraki Gulf. After the establishment of the wētāpunga on Motuora and Tiritiri Matangi we are looking forward to confirming establishment on other pest free islands, including Motuihe.

It’s very risky having the entire population of a species in one location so DOC, iwi and local communities work hard to keep islands in the Hauraki Gulf pest free so that initiatives like the breed to release programme can extend beyond those parameters to give these species a chance,” says Chris Green. 

Wētāpunga Fast Facts

1. Wētāpunga have been around more than 190 million years, around as long as our endemic tuatara, and have changed little over this time.
2. There are over 100 endemic species of wētā in New Zealand, including 11 species of giant wētā, of which wētāpunga are the largest
3. Adult female wētāpunga are heavier than males and on average weigh approximately 40 grams. The largest recorded female (gravid; with eggs) weighed 71 grams – heavier than your average house sparrow!
4. Females will lay eggs throughout their adult life, generally producing between 100 - 300 cigar-shaped eggs which remain underground for more than 8 months before hatching.
5. Wētāpunga go through 10 development stages or ‘instars’ before reaching adulthood, meaning they shed or moult their exoskeleton (outer covering) an incredible 10 times!  They achieve adulthood in approximately 15 – 24 months and can begin breeding one to two months after maturity. Adults can live for over a year, meaning their total lifespan from egg to adult is about three years.
6. Wētāpunga are nocturnal and feed mostly on fresh leaves and prefer native plants with large leaves such as karaka, karamu, māmāngi, māhoe, and kohekohe.
7. Premier pooper! For its size, the wētāpunga produces one of the largest poo pellets of any insects. It’s nutrient-rich and plays a vital role in the forest ecosystem by helping to germinate, fertilise and distribute plant seeds.