AUSTRALIA Zoo's Sumatran tiger, Kaitlyn, has safely delivered two critically endangered healthy tiger cubs - the first tiger cubs to be born in the zoo's 43 year history.

After going into labour at 11am yesterday, she delivered the first tiger cub at 5:07pm on and the second at 5:39pm on Thursday day.

At this stage Australia Zoo can't says whether they are male or female.

Both Kaitlyn and her cubs are healthy and doing well, according to Australia Zoo head tiger supervisor Giles Clark.

"We're so pleased with how well the birth went.

"Kaitlyn is a fantastic first time mum,'' Giles said.

"The cubs will spend the next few weeks bonding with mum. This will also ensure the cubs get the colostrum (first milk) and a head start while they are so small," he said.

After this, Giles will take over as mum, doing all the duties from feeding to toileting.

"At this time the strong bonds are formed between handlers and cubs to allow us to interact with the tigers for their entire life and provide the long term enrichment of walks and experiences outside of their enclosures.''

Visitors to Australia Zoo will have the opportunity to see the cubs in late October.

Kaitlyn is considered one of the most genetically valuable individuals in the world, as she was born to a mother who was wild born and a captive father.

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With less than 500 Sumatran tigers left in the wild, the birth of her cubs is a significant win for the future of the species.

"Not only will these cubs ensure the survival of the species in captivity, but they will also provide genetic diversity among captive tiger populations. The cubs' wild bloodline is an important factor.

These cubs are possibly the most significant births for the program in recent history," the Australia Zoo tiger handler said.

Australia Zoo’s Sumatran tiger, Kaitlyn,delivered two critically endangered healthy tiger cubs.

The new cubs will also play an important role acting as ambassadors for their wild cousins and raising much needed funds for conservation of these beautiful creatures in Sumatra.

"Tigers are listed as critically endangered, but it takes just $5 to save a tiger in the wild for one day.

Over the past decade, visitors to the Zoo have helped raise $1.3 million to support our tiger conservation projects around the world."

To see the cubs and mum on a live stream channel, visit www.australiazoo.com.au