Tuatara breed on mainland New Zealand for the first time for 200 years

10/11/2008 12:36:44 November 2008. Conservation staff at Wellington's world-first Karori Sanctuary have found what is almost certainly the first tuatara nest on mainland New Zealand in more than 200 years. The discovery came during routine maintenance work near the Sanctuary's unique mammal-proof fence, when staff uncovered the four ping-pong ball sized leathery white eggs.

‘This time last year we found a gravid (egg-carrying) female' said Sanctuary Conservation Manager Raewyn Empson. ‘We knew of two suspected nests but didn't want to disturb them to confirm whether or not they contained eggs. The nest in this photo was uncovered by accident, and is the first concrete proof we have that our tuatara are breeding. It suggests that there may be other nests in the Sanctuary we don't know of.'

Possibly 10 eggs
The eggs were immediately covered up again to avoid disturbing their incubation. Although only four eggs were unearthed, it is likely that there are more in the nest - an average clutch contains around ten. The eggs would have been laid almost exactly one year ago in a shallow trench dug by the female and then backfilled.

Neglectful mothers
Other than guarding the nest for a few days after laying to prevent other females digging the nest up, that is the end of maternal responsibility. All being well, the tuatara could hatch any time between now and March. The hatchlings will break out of the eggs using a special egg-tooth that will fall off after about two weeks. For the first six months or so the legendary ‘third eye' for which the tuatara is most famous will be visible as a white patch on the forehead. This too will disappear as the tuatara grows. As with some other reptiles, soil temperature will determine the animals' gender. Warm soil (over 21 degrees) results in males, and cool soil (under 21 degrees) females.

The first four tuatara eggs to be found in the wild on mainland New Zealand for perhaps 200 years, captured on camera by Karori Sanctuary conservation officer Matt Ward.

Only member of order
Tuatara are the only extant members of the Order Sphenodontia and endemic to New Zealand. Every other species in this Order became extinct about 60 million years ago, leading scientists to refer to tuatara as ‘living fossils'.

Reintroduced to mainland in 2005
It is uncertain exactly how long tuatara have been absent from mainland New Zealand but they rare if not extinct by the late 1700s due to egg predation primarily by rats (especially the kiore or Pacific rat). The re-establishment of a population at the rat-free Karori Sanctuary in 2005 was a breakthrough in re-establishing this species in the wild on mainland New Zealand. It has also made the species a lot more visible to the public.

70 animals were transferred to the Sanctuary in 2005 from Takapourewa (Stephens Island) in the Marlborough Sounds and gifted into the Sanctuary's care by their kaitiaki (guardians) Ngati Koata. Another 130 animals were released in 2007.

The Sanctuary was recently acknowledged as one of Australasia's top 25 ecological restoration projects by the Australia-based EMR Journal.