Creating a wētā future

Under a full moon and clear skies on an unseasonably warm evening in late June, I am hiking across Otata Island in The Noises, just 25km, but worlds away, from downtown Auckland.

I am here with Auckland Zoo's Ectotherms team leader Don McFarlane, his teammate Seth Garden and The Noises' Rod Neureuter to release 106 of one the world's heaviest and most spectacular insects, our largest endemic giant weta - the nocturnal weta punga.

The Noises have been privately owned by passionate conservationists the Neureuter family, since 1933. They are predator-free, and with the exception of Rangitoto, feature the best indigenous cover of all the inner Hauraki Gulf islands.

Otata (15 ha), the largest, supports a rich diversity of wildlife, marine and terrestrial - from grey-faced petrels that burrow all over the island, to little penguins, native geckos and the largest, plumpest and loudest tui population ever to be seen or heard. This spectacularly loud Otata tui choir broadcasts through the bush until it's almost dark and time to release our weta punga!

Auckland Zoo release weta punga on Otata in the Hauraki Gulf. Photo / Jane Healy

For this evening's release, Rod leads the way. In backpacks, Don and Seth transport their precious three to five-month-old charges (a safe release age), caught up and carefully packed into paper-padded plastic containers at 6am at Auckland Zoo's weta punga breeding facility.

It is perfect environmental conditions refined to create an explosion of weta by skilled Zoo staff at this specialist facility (the ultimate 'Weta Workshop') that has led to tonight's release. Here staff have bred thousands of weta punga since collecting their first breeding stock of six pairs from Hauturu (Little Barrier) in 2012.

Once widespread throughout Northland, Auckland and Great Barrier, the weta punga is today threatened with extinction, and only naturally found on Hauturu.

Auckland Zoo's curator of ectotherms and birds, Richard Gibson, explains:
"The Department of Conservation's (DoC) Chris Green and Paul Barrett at Butterfly Creek established a pilot programme through which they developed basic husbandry protocols for breeding weta punga. They carried out the first releases onto Tiritiri Matangi and Motuora islands, and we were delighted to join them in further populating these islands.

Following our unprecedented breeding success we were able to greatly increase the rate of reintroduction and more recently, as part of the recovery effort for the species as outlined in DoC's Weta Recovery Plan, extend the recovery effort to new islands in the Noises. None of this would have been possible without the continued support and enthusiasm of landowners, DOC colleagues and iwi," says Richard.

Auckland Zoo release weta punga on Otata in the Hauraki Gulf. Photo / Jane Healy

Auckland Zoo has permission to collect, breed and release weta punga until 2028, and recently collected a second founder population of 12 breeding animals from Hauturu to diversify genetics and rear a new wetapunga generation.

Tonight's release of weta punga onto Otata follows the release of over 1250 onto neighbouring Motuhorapapa in 2015. These animals are progressing well, are now sexually mature, and the Zoo hopes, will go on to produce the first generation of wild-born weta.

Don, Seth and Rod all agree that the 'Tane Mahuta' of Otata, a magnificent 800-year-old pohutakawa in the south-west valley is a great first home for 46 of these weta punga. The remaining 60 are released into 10 other mature pohutakawa across the rest of the island.

Once released, these cleverly camouflaged weta quickly climb and melt into the pohutakawa trees' flaky bark; the perfect refuge from natural predators like tieke (saddleback) or ruru (morepork) - the latter a bird we spotted at midday while scoping out release sites

Rod Neureuter is delighted to be working with Auckland Zoo and says "it is awesome to be putting an endemic species like weta punga back that may have been here once upon a time."

Through participating in several releases Rod is getting to know and love these unique arboreal invertebrates. He puts out his hands to willingly receive one of the last remaining animals to release, and the weta poos directly into his hands. He laughs, inspecting the offering. For its size, the weta punga produces one of the largest poo pellets of any insect and it's a great forest fertiliser!

"You're a lucky man Rod," enthuses Don, who like Seth is hugely impressed by Otata's variety, quality and quantity of food plant species for the weta, like mahoe, kohekohe, Pseudopanax (five-finger), Coprosma repens and taupata.

"This puts these weta punga in essentially a 'Charlies Chocolate Factory' with everything they could possibly need in easy reach to have the very best chance at survival," says Don.

Rod, who has been known to go out on a limb (literally!) to get rid of pest plants in precarious places on the islands, has grown up caring for this land and surrounding marine environment. These are values passed on from his parents and grandparents that just seem to be part of the Neureuter DNA.

Auckland Zoo release weta punga on Otata in the Hauraki Gulf. Photo / Jane Healy

"Our family cares deeply about these precious islands and are totally committed to their conservation for the future."

In 12 months' time, Otata and the Neureuter family should be receiving more Zoo-bred weta punga. Tonight's release cohort will also have reached adulthood, can be monitored (using tracking cards) and should be producing their own Otata-born generation.

"The more the merrier," says Rod.

Wētā punga (Deinacrida heteracantha)

Heavyweight champion
The wētā punga is the largest of New Zealand's 11 giant weta species and one of the world's heaviest insects. Females are heavier than males, usually weighing up to 35 grams but the largest ever recorded female weighed 71 grams when full of eggs - heavier than a house sparrow!

Ancient
Ancestors of the wētā punga have been around for more than 190 million years, pre-dating dinosaurs, and have changed little in this time.

Gentle giant
Wētā punga are gentle creatures. They will only bite if threatened or provoked, and the worst you'll get is a small nip.

Premier pooper
For its size, the predominantly vegetarian wētā punga produces one of the largest poo pellets of any insect. It's nutrient rich and plays a vital role in the ecosystem, germinating, fertilising and distributing plant seeds.
A freshly laid poo pellet weighs around 1 gram (same as a jelly-bean). On average, adult males weigh 20 grams and females, 30 grams

Ears on its 'knees'
Like all crickets and grasshoppers, the membranes that serve as a wētā punga's ears are located just below the knee joint of its front legs

A stand-out move

When provoked or threatened, wētā punga will make a rasping and clicking sound, and in a yoga move only they can do, will lift their spiky back legs over the top of their heads to ward off persistent predators.

Auckland Zoo release weta punga on Otata in the Hauraki Gulf. Photo / Jane Healy

• Jane Healy is Auckland Zoo’s senior media and communications co-ordinator.