A Maud Island frog, about the size of a fingernail, is seen at the Karori Wildlife Sanctuary in the capital of Wellington, New Zealand. The frogs were found breeding in the sanctuary, which may help to save the species.

Wellington, New Zealand ? A rare and threatened species of tiny frog has been found breeding in a New Zealand animal park, meaning its future may now be more secure, researchers said Monday.

The 13 fingernail-sized Maud Island froglets were discovered clinging to the backs of full-grown male frogs at the Karori Wildlife Sanctuary in the capital Wellington, said researcher Kerri Lukis. The frogs are normally found only on two islands in the Malborough Sounds region of New Zealand’s South Island.

“Maud Island frogs have never been found breeding” before, even on their home island, said Lukis, a masters degree student at Victoria University in Wellington.

“It’s wonderful timing for 2008 – International Year of the Frog and a Leap Year,” she said.

The breeding suggests Maud Island frogs can be bred in other predator-free habitats – strengthening their prospects for survival, said Ben Bell, the biologist overseeing Lukis’ studies.

The sanctuary’s predator-proof fence gives the frogs a breeding environment like Maud Island that is safe from rats, Bell said.

Maud Island frogs are estimated to number up to 40,000 – most of them on the island from which they take their name and the rest on Motuara Island.

Don Newman, who is the threatened species science manager with the Conservation Department, said the breeding success improves the species’ chance of survival.