Once widespread 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.
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.
Eating mainly at night, they feed 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 once a week, and are accustomed to feeding during the day.
Breeding is slow with tuatara they mate in summer and then lay their eggs the following summer up to 20 in a clutch. The eggs are covered with soil and left to hatch 13 to 14 months later.
Live to over 100 years old!
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 such as cats, dogs, ferrets, stoats, rats and possums.
Legally protected since 1895. Populations continue to decrease and on some islands they have become extinct.
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. Though it eventually regrows it may be a different colour.
Tuatara will whip with their tail, bite and scratch to escape danger.
At Hamilton Zoo we have one display tuatara, Hendrix, in the reptile house. A breeding group is maintained off-display, as are juveniles successfully bred at the zoo. Here eggs are usually collected and sent to Victoria University for controlled hatching. Juveniles will be returned to safe islands at around 5 years old.
Tuatara may live to over 100 years old. Sexual maturity is reached at about 20 years. 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' which can sense shadows
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.
Please remember that all reptiles are protected in New Zealand. None may be kept without a permit.