In 2007 Cook Strait Giant Wētā were successfully reintroduced into the sanctuary. This was a major conservation milestone for this species because they had been extinct on the mainland for over 100 years. Until the first 100 were transferred to ZEALANDIA from Matiu-Somes Island in February 2007. Since then another 275 have since been transferred from Matiu-Somes to ZEALANDIA between 2008 and 2010. Previous transfers had only been from one island to another. So returning them to the mainland in ZEALANDIA was an important part of their species restoration. This was the sanctuary’s 15th species reintroduced and first invertebrate. We are have seen signs of locally bred Giant Wētā at ZEALANDIA. This is a good sign of their success on the mainland, even with the presence of native predators like Ruru, Tuatara, and Tīeke in the sanctuary.
Wētā are a good food source for a lot of our native species. They are found throughout the bush environments and are an important part of New Zealand’s fragile terrestrial ecosystems. But with the continual arrival of people to New Zealand in the last 800 years came dramatic environmental changes. For the Giant Wētā habitat destruction, and predation from exotic species like Rats and Hedgehogs caused a dramatic decline in their populations. The Cook Strait Giant Wētā were reduced to populations on islands in the cook strait until they were reintroduced at ZEALANDIA.
At around 70mm long, and some females weighing up to 27g, the Cook Strait Giant Wētā are almost New Zealand's heaviest insects, but on average are lighter than 3 Giant Wētā species further north. They are a part of the Anostostomatidae family which includes king crickets and other wētā. This family of insects are spread throughout the southern hemisphere reflects the fragments of Gondwana.
Like other species of Wētā, the Cook Strait Giant Wētā are herbivores feeding at night on vegetation along the forest floor. During the day they hide in dark areas such as logs, to sleep and avoid predation by diurnal birds like the Tieke.
Usually only living for two years, female Cook Strāit giant wētā lay around 200 eggs in their second year. Male giant wētā can travel over 250 meters per night in order to mate with as many females as possible.