Page 3 – Decline and recovery
Despite large numbers of tuatara on some islands, populations continued to become extinct until recently. When Polynesian settlers arrived in New Zealand, about 1250–1300 AD, they brought with them kiore or Pacific rats (Rattus exulans), which preyed on tuatara. By the time of European settlement, in the 1840s, tuatara were almost extinct on the mainland. Some islands provided temporary havens, but soon these too began to be invaded by rats and other mammalian predators.
Legal protection was granted to tuatara and the islands they occupied in 1895, but the reptiles continued to decline. The most recent localised extinction was on Whenuakura Island, off the Coromandel Peninsula, around 1984. Since then, active conservation management has reversed the decline, and new populations have become established on predator-free islands.
Path to recovery
In the mid-1980s the New Zealand Wildlife Service and its successor, the Department of Conservation, developed ways to eradicate rats from islands. Rats have now gone from almost all of the tuatara islands, making them safe for many threatened native species.
In addition, collecting and incubating eggs, breeding in captivity, and moving tuatara to rat-free islands have increased the number of island populations to 37. In 2005, 70 adult tuatara from Stephens Island (Takapourewa) were moved to Karori Wildlife Sanctuary in Wellington – they were the first mainland population in hundreds of years. Many new tuatara populations are planned for islands and mainland reserves that have been freed of predators.
The case of Little Barrier Island (Hauturu)
On Little Barrier Island (Hauturu), in the Hauraki Gulf, a threatened population of tuatara was saved from extinction. In 1991 none had been seen there for 14 years, but the kiore were thriving. Tuatara were feared extinct from the largest island (3,000 hectares) on which they had previously lived. Surveys in 1991–92 found eight surviving adult tuatara, which were caught and housed safe from the rats. These eventually bred, their eggs were incubated in captivity, and the young were raised in rat-free enclosures. Kiore were eradicated from the island in 2004, and in 2006 the first of more than 100 young tuatara were set free. Committed action by scientists, conservationists, iwi (tribes) and volunteers has given hope that tuatara will once again be plentiful on Little Barrier Island.
Some Māori muttonbirders tell of an interesting use for tuatara on hot days. They would drape the cold-blooded reptiles across their stomach to cool themselves down. The effect would probably be short-lived – when tuatara warm up they become increasingly active.
Seeing tuatara in the wild
Until 1998, tuatara could be found only on island sanctuaries that were closed to the public. As an experiment, they were introduced to Somes Island (Matiu), in Wellington Harbour, and Tiritiri Matangi Island, near Auckland. Many people have visited these ecological restoration projects and seen tuatara.
In 2007, tuatara were most easily seen at the Karori Wildlife Sanctuary, 10 minutes from downtown Wellington. You will eventually be able to see them at other ecological restoration sites on the mainland.