Auckland Zoo is celebrating another step forward in its journey to secure a brighter future for New Zealand’s threatened wētā punga – one of the world’s heaviest insects.
Almost wiped out by introduced mammalian predators, the largest of Aotearoa’s 11 giant wētā species is today only naturally found on Hauturu (Little Barrier Island) in Auckland’s Hauraki Gulf. But this heavy-weight forest taonga (treasure), whose ancestry pre-dates the dinosaurs, is slowly making a comeback.
Since 2012, from 12 breeding animals collected from Hauturu, Auckland Zoo has led a highly successful breed-for-release programme that has now seen over 2,200 of these unique nocturnal invertebrates released onto four predator-free Hauraki Gulf islands.
In late June, Ectotherms team leader Don and colleague Kavi Chetty spent an exciting three-day weekend releasing a further 80 wētā punga onto pristine Otata Island (part of The Noises group) to bolster the first population released here this time last year.
Along with releasing these 80 animals, Don and Kavi also spent intense nights out in the cold and wet searching the island for evidence that last year’s wētā punga had made it to adulthood.
“It took 30 hours over three nights, but we did it! We found two adult wētā punga in great breeding condition – proof that these stunning animals are thriving and likely breeding. Any eggs laid that go on to hatch will be the first generation of wild-born weta here. Tracking cards we put out across the island also captured adult footprints. This is really the ultimate result, and such an incredible thrill. Looking at just one of these animals tracking around in the forest represents such a long journey and so much hard work by so many people to get to this point,” says Don.
These Otata releases follow the release of over 1250 onto neighbouring Noises’ island, Motuhorapapa, in 2015.
The Noises are just 25km, but worlds away, from downtown Auckland, and have been privately owned by passionate conservationists, the Neureuter family, since 1933. Thanks to their guardianship, these islands are wētā punga paradise, offering a great variety, quality and quantity of food plant species – everything from mahoe and Pseudopanax (five finger) to Coprosma repens and taupata.
“It puts these wētā punga in essentially a ‘Charlies Chocolate Factory’ with everything they could possibly need in easy reach to have the very best chance of survival,” explains Don.
Over the past five years, at the Zoo’s wētā punga breeding facility, the Zoo’s Ectotherms team has established perfect environmental conditions to create an explosion of wētā.
Last year, with DOC and relevant iwi’s blessing, the team was able to collect a second founder population of 12 animals from Hauturu in order to diversify genetics and rear a new wētā punga generation.
From these new animals, the team has to date bred 1500 more animals, and plans to release these new generation of wētā punga to Hauraki Gulf islands – Tiritiri Matangi, Motuora, and The Noises’ Otata and Motuhorapapa islands, this summer.
Auckland Zoo, which is working to achieve self-sustaining wētā punga populations on these islands, has permission from New Zealand’s Department of Conservation, to collect, breed and release wētā until 2028.
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 gravid female weighed 71 grams – heavier than a house sparrow!
Ancestors of the wētā punga have been around for more than 190 million ears, predating dinosaurs, and have changed little in this time.
- Poo power
For its size, the predominantly vegetarian wētā punga produces one of the largest poo pellets of any insect. It is 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.
- 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’s Content Advisor sat down with Don and Kavi to chat about their recent unforgettable weta punga weekend to listen to the podcast visit SoundCloud