(13 May 2010) Some of New Zealand’s oldest inhabitants are creating headlines with their unexpected breeding habits – proving there’s life in the old fossils yet.

For the second time in two months, New Zealand’s rare tuatara population has produced some surprising results with a new baby hatched at the Zealandia wildlife sanctuary and another eight on their way at Wellington Zoo.

The tuatara is a reptile unique to New Zealand, and the only survivor of a species that became extinct about 60 million years ago. Breeding is a tricky business and eggs can take up to a year to hatch.

Wellington Zoo
It’s the first time in 20 years that fertile tuatara eggs have been found at Wellington Zoo, and according to staff this represents a remarkable breeding success story.

In the world of old fossils where nothing moves quickly, it usually takes five years for a tuatara breeding pair to conceive.

However, in this case, the tuatara parents – father Tuatahi and mother Matamuri – were only introduced to each other at Christmas 2009, and the fact that they have already produced fertile eggs has astonished zoo staff.

The eggs were found by two of Wellington Zoo’s reptile keepers as they were digging Matamuri out of the earth in her enclosure for her April weigh-in.

Safe incubation
Excitement over the discovery was tempered with concern that disturbing the eggs would have a negative effect on their incubation.

The zoo’s tuatara species co-ordinator Barbara Blanchard sought advice and the eggs were transported to the Tuatara Recover Plan facility at Victoria University for safe incubation.

University senior technical officer Susan Keall said the eggs seemed dehydrated when they arrived, but since then had shown good signs of recovery.

“The signs are that they have picked up weight and plumped out again,” she said.

Although incubation could shorten the baby tuataras’ development it is unlikely they will hatch before the end of this year, according to the experts.

Eggs raised in warmer temperatures produce male tuatara and those incubated at cooler temperatures produce females, so four of the eggs are being kept at 23C and the others at 20C.

Difficult breeders
Tuatara are notoriously difficult to breed, and the last time any were successfully raised at Wellington Zoo was in the 1988 breeding season. The zoo currently has eight tuatara in residence.

Blanchard says the new babies will help contribute to the genetic diversity of the captive population of the reptile, as neither Matamuri nor Tuatahi have relatives or descendants in captivity.

Zealandia baby
Last month a baby tuatara spotted at Zealandia: Karori Sanctuary Experience in Wellington became only the second youngster born on the New Zealand mainland in over 200 years.

In 2005, 200 tuatara were released at Zealandia in a bid to boost the mainland population but babies were not expected this soon.

“Eggs are known to have been laid each year since the release, but we normally would not expect to see baby tuatara until they are much larger,” said chief executive Nancy McIntosh-Ward.

“We were overjoyed to find our first baby tuatara in March last year, now the discovery of a second youngster confirms that tuatara are successfully breeding in Zealandia – the only place on the mainland where tuatara live freely.”

She said it was assumed that there could be more youngsters at Zealandia but with the tuatara being so small in such a large area, it was difficult to monitor breeding.

Tuatara are the only extant members of the Order Sphenodontia and are 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’.

Websites:
Zealandia
Wellington Zoo

Tags: Wellington, Wellington Zoo, Zealandia

Posted: Thursday, 13-May-2010 at 13:19
Filed in categories: Wellington.
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