Not much is known about how or why, but the simple fact is that at some point a decade ago an entire species of tiny lizard vanished almost overnight from Christmas Island.

Key points: The blue-tailed skink disappeared from the wild on Christmas Island in 2010

The blue-tailed skink disappeared from the wild on Christmas Island in 2010 Local national park staff managed to capture 86 specimens at the last minute

Local national park staff managed to capture 86 specimens at the last minute Since then, they've bred 1,600 in captivity with a plan to one day reintroduce them

The blue-tailed skink, measuring only centimetres in length and featuring a bright blue streak down its back to its tail, is native to the remote island.

Only months before the mass die-off, Christmas Island National Park staff managed to scoop up 86 specimens from the rainforest floor in an effort to preserve rapidly declining numbers.

For reasons mysterious to them — although there are certainly theories — the skink was wiped out soon afterwards.

"We were like a second before extinction," said Kent Retallick, a senior reptile keeper at the park.

"The decline in the animal's population in the wild was so drastic and so dramatic that if nothing had been done when we did it we would have lost the species."

Kent Retallick has worked on the project to protect the skinks for the last decade. ( ABC News: Tom Joyner )

In the ten years since the skinks vanished in the wild, Mr Retallick and his team have pulled off something of a small miracle.

Hidden deep in the dense rainforest of Christmas Island is a sunlit shed containing row after row of clear enclosures, known as the Pink House.

It is there that they have managed to breed more than 1,600 healthy blue-tailed skinks from the original group of 86.

Through a process of trial and error, park staff have devised a diet of crickets and other insects gathered with a net from a lush area around the island's airport.

From an initial five enclosures, the facility has now grown to 40 to house the skinks alongside another endangered lizard known as Lister's gecko.

"I always remember the first two eggs that we ever found. It was one of the most amazing periods of time for me," Mr Retallick said.

From the original 86 blue-tailed skinks, island park staff have breed more than 1,600 at their facility. ( ABC News: Tom Joyner )

The plan, a decade in the making, is to one day reintroduce the skinks into the wild on Christmas Island.

Mr Retallick admits it is a wildly ambitious project, but said he is confident it has so far worked according to plan.

In January, he led a team to prepare the nearby Cocos Islands for the introduction of 150 skinks as part of a controlled experiment.

The implications of that trial, which followed extensive preparations and approvals before it could go ahead, will not be apparent for some time.

'It could take ten years'

Many endemic species have been threatened or even made extinct by invasive species on Christmas Island since human settlement more than a century ago.

The yellow crazy ant, for example, and first believed to have arrived on phosphate mining ships, has wiped out tens of millions of red crabs on the island since the 1990s.

The process of breeding the skinks has found success after an initial period of trial and error. ( ABC News: Tom Joyner )

But it was the decline of the pipistrelle bat in the 2000s that set in motion a review of endangered reptiles on the island, Mr Retallick said.

The father-of-two has dedicated a decade of his career so far to the preservation of the blue-tailed skink, and said he is in it for the long haul.

"It could take ten years [or more]. So what I don't want to do is get all excited about it," he said.

Should something happen to the captive bred population of skinks on Christmas Island — disease or fire, for example — the park staff have a backup.

A conservation team at Taronga Zoo in Sydney, more than 5,000 kilometres away, have bred their own skinks as an 'insurance' population.

An 'insurance' population of blue-tailed skinks is kept at Taronga Zoo in Sydney. ( ABC News: Will Ockenden )

In two rooms at the facility on the shores of Sydney's harbour, hundreds of blue-tailed skinks and Lister's geckoes are kept in glass enclosures.

Between Christmas Island and Taronga Zoo, a lot of money and work has gone into protecting the last of the two species.

But there is little doubt among any involved that the work is vital and contributing to a larger pushback against the devastation caused by invasive species nationwide.

"Every animal has a slight role in the ecosystem," said Michael McFadden, a fauna supervisor at the zoo.

"For a blue-tailed skink, that was formerly common all over the island, I have no doubt that the prey species they used to feed on have increased."

Blue-tailed skinks are fed a diet of crickets and other insects while kept in captivity. ( ABC News: Will Ockenden )

Mr McFadden said conservation authorities may not always have a solution to protect vulnerable species, but that did not preclude finding one in the future.

"Something that might not be easy to mitigate or re-establish in the wild now, in five or ten years' time we might have a silver bullet," he said.

Until that time, the blue-tailed skinks will continue to live in captivity.