Wētāpunga are the largest of New Zealand's 11 species of giant wētā and have been in existence since the age of dinosaurs. Photo / Wendy Brown
Hundreds of the world’s largest insect have been released on to Whangārei Harbour’s predator-free Matakohe-Limestone Island, marking another milestone in the island’s 35 years of biodiversity restoration.
The occasion, which took five years of careful planning, involved about 450 giant wētā (wētāpunga) – adults and juveniles – being released on May 5, with about 50 members of local iwi, school students, volunteers and Friends of Matakohe-Limestone Island barging from Onerahi to take part.
The wētāpunga – the biggest of New Zealand’s 11 giant wētā species – stem from the sole surviving natural population on Te Hauturu-o-Toi / Little Barrier Island and were raised at Auckland’s Butterfly Creek.
Butterfly Creek has run a breed-to-release programme for 15 years, restoring wētāpunga across several Hauraki Gulf islands.
Encapsulated in bamboo tubes and packed into chilly bins at about 4am on May 5, they were safely transported to their new home and formally handed over on the island by members of Auckland iwi Ngāti Manuhiri to mana whenua Te Parawhau.
Formalities included a reveal by Butterfly Creek staff of an adult female wētāpunga, which measure up to 10cm long, with a total leg span measuring up to 20cms, and can weigh as much as a small bird.
Friends of Matakohe-Limestone Island chairwoman Pam Stevens said the species’ heavy-duty body was a reminder it had been around since the age of the dinosaurs.
Attendees then helped choose new homes for the insects, nestling the bamboo containers high in the branches of preferred food trees – broadleaf species like pūriri, karaka and the kohekohe – for which the island was originally named.
“We put them in the trees with cable ties ... then took off the gauze for them to come out overnight.”
They are expected to venture out mostly at dusk, feeding on flowers, fruit and leaves.
Stevens described the transfer as an “extraordinary achievement – one the whole community can cherish” and “a special occasion for a special island”.
The project, which cost about $15,000 and required specific consents, was funded by Foundation North with support from Golden Bay Cement and other sponsors.
Giant wētā were once abundant in Northland but numbers have declined significantly over time because of introduced predators.
“The young are bred on the ground ... then they get nailed by rats and mice,” Stevens said.
She said the species’ introduction at Matakohe-Limestone builds on more than 35 years of work to transform the 37-hectare island into a predator-free sanctuary, now renowned for its kiwi creche breeding programme.
Matakohe-Limestone Island, in the middle of Whangārei Harbour, has been occupied by humans for much of its history. It was once a significant and strategic pā site, with remains of extensive kūmara gardens still evident on its northern slopes. From the late 1850s to 1920, settlers operated cement works on the island, the jumbled concrete towers of which still stand today.
For the next 70 years, the island was largely neglected, not becoming a focus again until biodiversity restoration efforts began in 1989.
Since then, with the steadfast support of Te Parawhau iwi, thousands of hours of volunteer labour and critical financial backing from sponsors, pest animals and plants have been systematically removed, and more than 200,000 native trees and shrubs have been planted, Stevens said.
“The island is invigorated; it shows in the variety of wildlife flourishing here – young kiwi wander, safe in their island creche, pipits, fernbirds and numerous other bird species fly in and around, along with geckos, skinks, stick insects, tree wētā ... ”
Next on the list? Native snails and giraffe beatles, Stevens said.
According to the Department of Conservation, New Zealand is home to more than 70 endemic species of wētā, including 11 species of giant wētā, with the wētāpunga the largest of them all. Adult females can weigh up to 35 grams – heavier than an average house sparrow – and can take up to two years to reach maturity, shedding their exoskeleton up to 11 times before becoming fully grown.
Wētāpunga live for six to nine months as adults, during which time they breed and lay between 100 and 300 eggs in the soil. Conservation breeding programmes at Butterfly Creek and Auckland Zoo have played a key role in the species’ recovery, raising wētāpunga for release into predator-free habitats to help restore wild populations.
Sarah Curtis is a news reporter for the Northern Advocate, focusing on a wide range of issues. She has nearly 20 years’ experience in journalism, most of which she spent reporting on the courts in Gisborne and the East Coast.