Tuatara © 3 News

GENUS: Rhynchocephalia

SPECIES: Sphenodon

The Tuatara’s closest relatives are other subspecies of Tuatara, as no other species from the same ‘order’ survive today.

Three different species of Tuatara in New Zealand:

• - Northern Tuatara (Sphenodon Punctatus Punctatus)
  
• - Cook Strait Tuatara (Sphenodon Punctatus)
  
• - Brothers Island Tuatara (Sphenodon Guntheri)

The scientific name of the species means ‘spotted Tuatara’, with the maori name interpreted as ‘spiny back’.

Colour: grey, olive or occasionally brick red

Size: males are up to twice the size of females and may grow up to 60cm in length and weigh up to one kilogram.

Distinctive Features: scaly, dappled skins with a soft spiny crest ridge extending from the head, down the back to the tail.

Tuatara are egg laying and cold blooded

The Tuatara has a legendary ‘third eye’, part of a complex organ situated at the top of the brain. This organ contains a lens, retina and nerve connection to the brain, but is covered by opaque scales early in its growth. The function of this ‘third eye’ is not known, but it possibly acts as a light sensor.

STATUS: Rare

Tuatara are recognised both internationally and in New Zealand, as a species at risk. Once plentiful, the Tuatara has declined since the arrival of humans in New Zealand due to loss of habitat and food supply and the introduction of predators.

GEOGRAPHICAL DISTRIBUTION:

Islands provide sanctuary for mainland dwellers. In order to preserve this formerly mainland species, the Stephens, Trios and Brothers groups of islands, as well as selected islands off the North Island coast line between the Bay of Islands and Tauranga, have now become their translocated home. With no predators here, they may breed and feed undisturbed.Link to our Poor Knights Islands web page for more information on a typical Tuatara island home.

HABITAT:

Where there are burrows you might well find Tuatara.

Tuatara need to be in areas where burrowing seabirds are found, particularly petrels and shearwaters. The seabirds provide ready made burrows and large deposits of droppings around which insects gather and breed. They also enjoy coastal forests and clearings – cool areas to which they are specifically adapted.

FOOD:

Nocturnal carnivores.

Tuatara are night-time foragers, sometimes climbing trees to do so. Being meat eaters, insects such as beetles, spiders, crickets and weta make up the main proportion of the Tuatara diet. Sometimes small seabirds, frogs and lizards make their way onto the menu.

With two rows of upper teeth fitting neatly around one row of lower teeth, the jaw can move backwards and forwards, a neat tool for ripping apart prey. Holes in their skulls give extra power to their jaws, allowing them to hold prey until it dies.

ABOUT THE TUATARA:

The living dinosaur.

Although often thought of as a lizard, the Tuatara is a reptile and the sole survivor of an ancient line of reptiles known as Sphenodontia. With the exception of the Tuatara, this line, once very common in Africa, North America and Europe, died out about 60 million years ago. It may once have lived in the sea as it has no outer ears and vertebrae similar to those of a fish.

Being nocturnal, Tuatara are mostly active at night, staying hidden from predators under rocks, logs and in burrows during the day. If apparent in daylight hours, they will most likely be seen sunning themselves on rocks or outside their burrows. Despite their sleepy appearance, they will probably be waiting for prey to walk unwittingly by.

Like many lizards the Tuatara is able to shed its tail, the regrowth differing in colour from the shedding and shorter in length.

Mating takes place in late summer and early autumn and eggs are laid the following spring. The female will lay between 1-18 soft-shelled eggs in a small burrow, covering them with leaves and soil for protection. She will check the eggs for 2-3 nights, then leave, never to return. Only 2% of the eggs will hatch! Young Tuatara cut their way out of the egg with an ‘egg tooth’ after 12-16 months. They will be about 10cm long and take a lengthy 13-20 years to mature and 60 years to reach full growth. A Tuatara may live to 100 years old, given the opportunity, maybe up to 300!

THREATS:

Rats, poaching and habitat destruction threaten our unique endemic reptile. All island groupings of Tuatara face common threats. Norway rats, ship rats and the native kiore may be the single greatest threat to both eggs and young, as Tuatara cannot seem to persist when these predators are present.Fires destroy Tuatara habitat, although they may not lead to extinction of populations. Poaching, however, does pose a threat. The extent of its impact is not known, but Tuatara fetch a considerable price on the rare species black market.

Despite legal protection (see below), Tuatara numbers and habitats continue to decline. Since Polynesians arrived in New Zealand, the habitat occupied by Tuatara has fallen to probably 0.5% of its original range. Within the last 100 years, at least 10 of the 40 known offshore island populations have become extinct. At least four of the remaining 30 populations are likely to go the same way within approximately 50 years. The Brothers Island Tuatara is particularly vulnerable, existing on one tiny island in the group and consisting of only a few hundred individuals.

WHAT’S BEING DONE?

The unique status of this reptile was no doubt instrumental in its protection by law. Way back in April 1895 a warrant gave absolute protection and in September 1898, it’s eggs were given protected status as well.

The New Zealand Department of Conservation monitors the tuatara breeding programme on offshore islands, keeping these islands free from introduced predators and protected from loss of habitat. Supervised breeding programmes keep specimens under controlled heat to ensure that they thrive. Behaviour and survival skills are carefully watched to develop an understanding of this creature necessary for its management in the wild.

Most offshore island Tuatara refuges are cliffbound and difficult to access. All but one have ‘nature reserve’, ‘scenic reserve’ or ‘wildlife sanctuary’ status and require DOC permission to visit. The exception is Moutoki, which is Maori owned and requires owner permission to visit.

WHAT CAN YOU DO?

Be aware and take care.

Keep predators off the islands! Be aware of those islands that are Tuatara sanctuaries and keep your boat at a distance. One rat, cat or dog can do an enormous amount of damage to Tuatara populations.

Support wildlife initiatives by conservation organisations. Link to the Department of Conservation or non-governmental organisation websites and offer your time, money or energies as a volunteer or patron of these projects.

SAVE THE TUATARA!