The tuatara population on Hauturu ō Toi/Little Barrier Island may be recovering, according to results from a recent survey carried out with help from Victoria University of Wellington researchers.
Since the early 1990s, an intensive tuatara conservation recovery programme has been run on the island, where the species had not been seen for 10 years.
In a collaboration between Victoria University, Department of Conservation (DoC), local Mana Whenua Ngati Manuhiri, Auckland Zoo and the Hauturu Supporters Trust, the programme has helped to save a threatened population of tuatara from extinction. The initiative has included eradicating pests on the island, which was declared rat-free in 2006.
During an eight-day survey in January this year, volunteers found four unmarked tuatara. Sue Keall, a technician in Victoria’s School of Biological Sciences who helped carry out the survey, says this provides positive insight into how the tuatara are surviving.
“The young tuatara could have been bred from existing wild tuatara that were not seen during the original surveys, or from captive-bred tuatara that had been released on the island by the programme,” she says.
“We aren’t able to tell their age, but it is fantastic to know the wild population might be able to successfully breed again, now that cats and kiore (Pacific rats) have been eradicated.”
A number of areas on the 3,000-hectare island were identified for searching, based around where tuatara had been caught during the first survey period, locations where there had been reported sightings, or sites where they had been released from the breeding programme.
The programme sends tuatara eggs laid on the island to Victoria University to be incubated and hatched.
“Incubation at the university keeps them a bit safer—it stops the eggs from drying out or getting dug up accidentally by other tuatara on the island. We’re simply maximising their chances of success,” says Ms Keall.
The young tuatara are then returned to Hauturu ō Toi/Little Barrier Island for release.
Surveyors also spotted the endangered Duvaucel’s Gecko on the island, indicating this species is also in recovery after removal of kiore. Ms Keall, who was in the first survey team 23 years ago, says the island is showing encouraging signs.
“Because it’s such a large island and also is quite high in altitude, it retains a variety of vegetation types making it a really good varied habitat. It’s very exciting seeing species that were really struggling now starting to recover on the island.”
In August last year, Victoria University published rare footage of a tuatara hatching. The tuatara filmed was an offspring from the programme.
Watch it here: www.youtube.com/watch?v=9Ar4hG8b534
