ZOO bosses are over the moon about their newest arrivals – which are boosting the population of one of the world’s most threatened creatures.

Three Sumatran tiger cubs have been born at Flaming Land zoo near Pickering, North Yorkshire, and are about to be allowed outside for the very first time.

The cubs, two female and one male, were born on March 22 to the zoo’s own breeding pair – mother Surya and father Bawa – and have yet to be named.

It is estimated that the world population of Sumatran tigers is now as low as 400 – so the new arrivals have boosted that figure by almost one per cent.

“We are extremely proud,” said a spokesman. “This is a significant figure and helps make a real difference.”

“It is also good that the cubs are of both sexes – they will be able to go on and do their bit to improve the population in the future.”

The average life expectancy of Sumatran tigers in the wild is only four years, but the expected lifespan of Surya and Bawa is more than 20 years.

They are both about five-years-old and have both been at the zoo for two years, Bawa coming from the Wildlife Help Foundation in Kent and Surya from Paignton zoo in Devon.

“We can now look forward to many more productive years for our breeding pair as a vital part of worldwide conservation efforts to save this species from extinction,” said the spokesman.

The zoo’s vet has now indicated the cubs are ready to be released into the outside enclosure and go on show for the first time – and the hatch is due to be lifted on Wednesday morning.