The two species of tuatara (Sphenodon punctatus and S. guntheri) are the only remaining species from a once diverse group of reptiles called Rhynchcephalia. Once upon a time, different species from this group inhabited land, trees and water. Now they are only found in a few forests of New Zealand. Of all the other reptiles, the tuataras are most closely related to snakes and lizards.
Tuatara are modest size reptiles and grow up to 60 cm long. They have a line of spikes that runs down the length of their spine. Their spikes gave them the name ‘Tuatara’ which means ‘spiny back’ in Te Reo Māori, the language of the indigenous people of New Zealand.
Being reptiles, tuatara are cold-blooded but they are also nocturnal animals. This makes it difficult to keep their body temperatures up during the time they are most active. Body temperatures during the night usually range between 6-16°C, considerably lower than lizards. They bask during the day and reach body temperatures of up to 28°C.
Where are Tuatara found?
Natural populations are found only on a number of offshore islands of New Zealand. Before the arrival of humans, tuatara were found through both the North and South Islands but humans and introduced mammalian predators forced the extinction of mainland populations around 800 years ago. In recent years they have been returned to the mainland in protected sanctuaries.
Tuatara feed primarily on invertebrates but occasionally eat lizards, frogs and sea birds. They have two sets of upper teeth and a single row of bottom teeth. The bottom row slots in between the two rows of upper teeth.
Most of their food comes either directly or indirectly from sea bird colonies. Sea birds provide food for their young which attracts large numbers of insects and other invertebrates for the tuatara to feed on. Birds that can easily be caught during the night also provide an important energy source. It is possible that the nocturnal lifestyle is a result of the relationship tuatara have with the sea bird colonies as the invertebrates they provide can only be efficiently hunted during the night.
Tuatara live on foggy offshore islands in burrows that are often shared with sea birds. They live in dense colonies with burrows separated by 2-3 m. Both females and males are territorial.
Last edited: 17 December 2015