A tiny rainbow-hued lizard which all but disappeared from the wild 10 years ago has been given the run of a brand new home — its very own tropical island off the WA coast.

Key points: The skink was last spotted in the wild about 10 years ago

The skink was last spotted in the wild about 10 years ago A breeding program has grown 66 in captivity to more than 1,500

A breeding program has grown 66 in captivity to more than 1,500 Many will now be released on an island that has been cleared of predators

The critically endangered blue-tailed skink became virtually extinct back in 2009, but a breeding program run by Parks Australia and Taronga Zoo has seen their numbers swell to about 1,500 in captivity.

Just 66 blue-tailed skinks were captured by Parks Australia in 2009, after the once prevalent species' numbers began to rapidly decline on their home of Christmas Island.

The skinks have been introduced to a tiny island about 1,000km away from their old home. ( Supplied: Parks Australia )

Parks Australia threatened species national resource manager Brendan Tiernan has been at the heart of the recovery and breeding efforts to preserve the brightly coloured reptiles, traversing rough terrain to the very edges of the island to capture some of the animals before they completely disappeared.

"They're quite a spectacular looking little lizard," Mr Tiernan said.

"They have obviously a bright blue shimmering tail, but the rest of their body is also quite colourful, almost rainbow in appearance … sort of a golden back and the front of the lizard, around the head, they're almost a brassy burnt-red colour."

He said the tiny lizard weighs about 2.5 grams and measures 10 centimetres long.

Parks Australia's Brendan Tiernan collected some of the last blue-tailed skinks from the wild before they disappeared. ( Supplied: Parks Australia )

On Saturday 150 of the animals were released onto Pulu Blan, a tiny island just 2 metres above sea level at its highest point, which is part of the archipelago making up the Cocos (Keeling) Islands 2,150 kilometres off Australia's north-west coast.

They were flown from Taronga Zoo, which has been one of two captive breeding sites for the animals.

More of the skinks specially bred on Christmas Island would also be relocated to the island.

'Little lizards with ADHD'

Mr Tiernan said they decided on the island release site because it was free of the predators believed responsible for the skinks' decline.

The animal believed responsible for their disappearance is the Southeast Asian wolf snake, which was spotted in the wharf area of Christmas Island in the late 1980s.

Shortly after that the blue-tailed skinks were pushed to the wilder, outer rim of the island and the difference was obvious.

The blue-tailed skinks are very active lizards. ( Supplied: Parks Australia )

"When they were in the wild they were quite gregarious and arboreal (tree-dwelling), always moving around, chasing little patches of sunlight," Mr Tiernan said.

"And they were very obvious when they were there, because they were basically little lizards with ADHD, they couldn't sit still for more than a second at a time, … they were quite a sight when they were out in the wild."

Mr Tiernan said while there were some differences, Christmas Island and the Cocos Islands shared a similar climate.

"Christmas Island is a rugged, mountainous karst limestone landscape, also [it] has a fair bit of intact vegetation and habitat left on it," he said.

The Cocos (Keeling) Islands are covered in coconut palms and girt by turquoise blue water. ( Supplied: Rik Soderlund )

"Whereas Cocos is the idyllic holidaymaker's/beachgoer's beautiful turquoise blue landscape.

"It's also highly modified, it's been planted with coconuts so there's very little native vegetation left."

Ultimately there are two islands in the Cocos archipelago onto which the skinks will be released.

Christmas Island is home to many unique species, including its iconic red crabs. ( ABC News: Tom Joyner )

Taronga Zoo herpetofauna department supervisor Michael McFadden, who was involved in the breeding program, said he had to work out the social dynamics such as how many males and females could be housed together.

"They bred quite readily, we were able to breed quite large numbers in a short space of time, which will really help facilitate the ongoing reintroduction program to try to re-establish these guys back in a wild scenario," he said.