In New Zealand, a female wētāpunga (Deinacrida heteracantha) can weigh up to seventy grams — roughly as much as an adult mouse. Until recently, this giant wētā, which once inhabited vast areas of the North Island, survived on only one tiny patch of land — Little Barrier Island. Today, after fifteen years of dedicated work, the species has moved from the category of nationally endangered to nationally recovering.
The cause of the sharp decline is a classic story of human pressure. European settlers cleared forests for pasture and, along with them, introduced rats, stoats and other predators for whom the heavy, slow-moving insects were easy prey. By the nineties of the last century, the wētāpunga was considered extinct on the mainland, and on the single surviving island the population was rapidly shrinking.
Instead of trying to relocate the last individuals directly, the specialists chose the path of captive breeding. Beginning in 2010, tens of thousands of insects were bred at Butterfly Creek, and later also at Auckland Zoo. Over fifteen years, forty-five translocations were carried out and more than eleven thousand individuals were released into the wild on eight predator-free islands and in two fenced mainland sanctuaries.
The most convincing sign of success has appeared on Motuora and Tiritiri Matangi islands: the fourth and even fifth generations born in the wild have already been recorded there. This means that the populations have become self-sustaining and no longer depend solely on new releases. Such a result for invertebrates is extremely rare and is regarded as an international benchmark for successful reintroduction.
A partnership with the local Ngāti Manuhiri tribe — the traditional guardians of Little Barrier Island — played an important role. Their knowledge and participation helped not only in the practical work but also in long-term planning. The experience gained in saving the wētāpunga is already being applied to other species of giant wētā that are under threat.
The success of the programme shows that even for large invertebrates, which are often overlooked in favour of more "charismatic" animals, real progress is possible if a scientific approach, large-scale breeding and habitat protection are combined.
