Tuatara

(Sphenodon punctatus)

Live: Tuatara now mainly occur only on islands that are free from rats, cats, dogs and pigs. There are also eight islands which support tuatara where the Polynesian rat (kiore) is present. Studies on these islands indicate that these tuatara populations are ageing, which suggests that the kiore prey on young tuatara. 

Habitat: The habitat of this special reptile used to be widely spread across Aotearoa/New Zealand. Since becoming extinct on the mainland, they are restricted to coastal shrub and bush areas on isolated islands which have been cleared of introduced predators.

Diet: Tuatara eat mainly at night, feeding on insects and other small animals. Much of the day is spent in the burrows, often shared in the wild with a family of petrels!
In the Zoo they are fed insects, meat and vegetables 3 times a week, and are accustomed to feeding during the day.

Breeding: Like most reptiles, tuatara lay eggs, up to 20 in a clutch, usually in early summer. Sexual maturity is reached at about 20 years. The eggs are covered with soil and left to hatch 13 to 14 months later. At the Zoo, eggs are usually collected and sent to Victoria University for controlled hatching. The hatchling has a pointed tip to its snout to enable it to break out of the leathery egg. They are self-sufficient at hatching.

At Hamilton Zoo we have one display tuatara, Hendrix, in the old reptile house. A breeding group is maintained off-display, as are juveniles successfully bred at the Zoo. Juveniles will be returned to safe islands at around 5 years old.

Conservation status: The tuatara has been legally protected since 1895. Populations continue to decrease and on some islands they have become extinct.

General: Tuatara is a Maori word meaning 'peaks on the back'.
Although similar in appearance, the tuatara isn't a lizard.

The tuatara is the only surviving member of an ancient group of reptiles, the Rhynchocephalia, which means 'beak-head'. The oldest fossils of tuatara are found in rocks of Jurassic age -180 million years ago. Fossil evidence indicates that the other members of Rhynchocephalia have been extinct for 60 million years.

Why isn't it a lizard? The only obvious difference you'll be able to see is the external ear opening, which is present in lizards but absent in tuatara.

They are well-muscled, have sharp claws and partially webbed feet. Care must be taken when handling as the tail can break off. (It will eventually regrow but may be a different colour.) Tuatara will whip with their tail, bite and scratch to escape danger. Removing Hendrix from his burrow when he is not inclined to leave is a difficult task for the keeper!

Tuatara may live to over 100 years old. Males may weigh more than 1kg. Females are smaller and rarely exceed 500g in weight. In captivity they may grow larger than in the wild. They grow slowly and may still be growing at age 50.

Other amazing facts:
Tuatara have a tiny 'third eye'.
Males have no sexual organ.
They can swim well.
They can be active between 7 and 22 degrees Celsius. (Most other reptiles would hibernate at such low temperatures.)
Their teeth are extensions of the jawbones; when they wear out they are not replaced. They don't fall out either!
There is no letter 's' in the Maori language, so the plural of tuatara is tuatara.

Predators: Before humans arrived, the only predators of the tuatara were large birds of prey. As tuatara can reach lengths of 75cm (2 feet), it is the young that are most at risk from introduced predators. Cats, dogs, ferrets, stoats, rats and possums will also kill them.
By European times they were found only on the offshore islands. There is evidence of tuatara remains in the middens of the early Maori, but in more recent times they were treated as tapu and therefore not eaten or hunted. Their decline on the mainland was probably due to habitat changes such as forest clearing (deforestation), and to the introduction of the Polynesian rat, kiore.
At least nine other populations appear to have become extinct this century, including two since 1980. The loss of these populations was probably caused partly by introduced predatory mammals and partly by changes to the habitat itself.

Please remember that all reptiles are protected in New Zealand. None may be kept without a permit.