Tuatara: New Zealand's living dinosaur

The tuatara is a lizard-like reptile - often described as a living fossil from the dinosaur age - that is only found in New Zealand.

Populations of the rare and curious tuatara - one of the world’s oldest species - can be found on certain small islands around New Zealand and in a growing number of mainland sanctuaries where visitors can have the rare privilege of meeting this dinosaur survivor.

Tuatara can live to a ripe old age and the most famous among his peers, is 118-year-old Henry who lives at the Southland Museum & Art Gallery. Henry’s sexual exploits and fatherhood have earned him regular press as the star turn in the museum’s highly successful breeding programme, and he was recently seen on the arm of his namesake Prince Harry of England.

The tuatara is not a true lizard but a 'living fossil' - a survivor from an ancient group of species. While it looks very much like a lizard, the tuatara skeleton has many differences.

This ‘living fossil’ is the one remaining member of the Order Sphenodontia which was represented by many species during the age of the dinosaurs, some 200 million years ago. All species apart from the tuatara declined and eventually became extinct about 60 million years ago.

Endangered species

While large numbers of tuatara are living on some islands, and breeding programmes are proving successful, the species remains endangered by predation.

When Polynesian settlers arrived in New Zealand, about 1250 - 1300AD, they introduced kiore / Pacific rats which preyed on tuatara. By the time European settlement began in the 1840s, the tuatara was already almost extinct on the mainland.

While some islands provided temporary havens, these too were eventually invaded by rats and other mammalian predators that arrived along with European settlers. As early as 1895, legal protection was granted to tuatara and the islands they occupied, but the reptiles continued to decline.

Early conservation work

In the mid-1980s, the New Zealand Wildlife Service and its successor, the Department of Conservation (DOC), began to develop ways to eradicate rats from islands. Nowadays these predators are gone from almost all of the tuatara islands, making them safe for this and other threatened wildlife.

In addition to eradicating predators, other measures to protect tuatara were introduced such as collecting and incubating eggs, captive breeding programmes, and moving tuatara to rat-free islands.

Tuatara populations are now found on around 35 islands. Seven of these islands are in Cook Strait – between Wellington on the southern edge of the North Island and Marlborough – Nelson at the tip of the South Island – and are home to an estimated 45,500 animals.

A further 10,000 northern tuatara are spread over islands around the northern end of the North Island – near Auckland, Northland, the Coromandel Peninsula and the Bay of Plenty.

Conservation efforts

Hauturu / Little Barrier Island, in the Hauraki Gulf between Auckland and the Coromandel, is an example of how a threatened tuatara population has been saved from extinction through conservation initiatives.

When DOC started a captive management programme on Little Barrier in 1991, no tuatara had been seen on the island for 14 years - though the rats continued to thrive. Then eight surviving adult tuatara were discovered, captured and held safe from the rats.

As a result of the safe environment, the tuatara eventually bred. The eggs were incubated in captivity, and the young were raised in rat-free enclosures. By 2004, kiore rats had been completely eradicated from the island allowing young tuatara to be released back into the wild in 2006.

Tuatara in the wild

Until 1998, tuatara could only be found on island sanctuaries that were closed to the public.

As an experiment, to make them more accessible, they were introduced to Matiu / Somes Island, in Wellington Harbour, and Tiritiri Matangi Island, in the Hauraki Gulf near Auckland. Many people have now visited these ecological restoration projects and seen tuatara living in the wild.

In 2005, 70 adult tuatara from Takapourewa / Stephens Island were introduced to Wellington’s Zealandia wildlife sanctuary. They were the first mainland population in hundreds of years and these are now thriving in the midst of the urban eco-sanctuary.

This success has led to the introduction of populations of tuatara into mainland sanctuaries such as Sanctuary Mountain at Maungatautari, near Hamilton. There is also a breeding programme at Rotorua's Rainbow Springs wildlife centre.

A living dinosaur

A New Zealand native, the tuatara is a rare, medium-sized reptile. An adult can grow up to 24cm in length and weigh about 500 grams.

Though there are physical resemblances, the tuatara is very different to lizards, crocodiles and amphibians. Their primitive body structure suggests that they have changed little in the past 220 million years, making them one of the world’s oldest and most un-evolved species. The Māori translation of tuatara is ‘spiny back’.

The tuatara is vulnerable to predators as they are slow breeders. Females lay soft-shelled eggs nine months after mating, and the eggs take 12 - 15 months to hatch. The sex of the baby is determined by the soil temperature.

It takes anything from 9 - 14 years for a juvenile tuatara to mature, and they reach their full size at 25 - 35 years old. The tuatara lives for 60 to 100 or more years.