KEY POINTS:
Fourteen tuatara have been released in their ancestral homeland of Cuvier Island, off the Coromandel Peninsula.
The three year-old tuatara are of the Cuvier species and were reared in captivity at the Auckland Zoo.
The zoo's fauna team leader, Andrew Nelson, said they will boost the island's population, estimated to be 30, by about 50 per cent.
"Tuatara are both incredibly slow breeding and slow growing but now, with all of them over 80 grams, these guys are big enough to defend themselves against natural predators like birds and adult tuatara," Mr Nelson said.
He said there is plenty of food for them on Cuvier which was cleared of kiore, or Pacific rat, in 1993.
Department of Conservation ranger, Rob Chappell, said the tuatara were hard to find on the island but there was evidence that they were doing well.
"Last February when the zoo released two juveniles, we came across one of the tuatara we released back in 2003, clearly thriving in Cuvier conditions."
He said tuatara don't reach sexual maturity until they're 14 years-old and they can wait many years until they decide to breed.
Mr Chappell said a significant increase in the population was decades away.
"We're on tuatara time here," he said.
The Auckland Zoo received six tuatara from the Department of Conservation in 1990 and has since bred and released 34 tuatara on to Cuvier.
- NZHERALD STAFF
