A Giant Panda mum surprised her zoo keepers by giving birth to not just one but two cubs.
Zookeepers had only been expecting just one after scans on mum Yang Yang did not reveal the other cub.
And the twin cubs are now less than a fortnight old and doing well as these adorable pictures show the mum cleaning and feeding her babies with their “fat little tummies.”
At just 15cm long, the cubs are barely bigger than the average person’s hand, zookeepers at Schönbrunn Zoo revealed.
While the twins have far less hair than their mum, they are growing fluffier by the day and their distinctive black and white coats are already beginning to grow.
Zoo director Dagmar Scratter said the arrival of twins, on August 7, came as a shock to keepers.
Dagmar said: “It had sounded as if there were two young animals squeaking, but the pictures only ever showed one.
“On Friday the keepers could see two babies on the screen for the first time.”
Giant Pandas are an endangered species, with about 1,600 left in the wild and just over 300 living in captivity.
Twins are fairly common in the species, but the mother usually only rears the stronger of the two.
While the cubs appear to be developing well so far, zoo keepers will be watching from a far and been unable to find out if the twins are a boy or a girl.
Dagmar added: “As we believe in natural rearing, we will simply be watching via camera what is happening in the breeding box.”
Sadly, half of all newborn pandas will die in their first few weeks.
This is why, according to Chinese tradition, pandas are only named after 100 days.
Zoologist Eveline Dungl said: “Both little pandas have fat little tummies and panda mother Yang Yang is totally relaxed.
“The little ones can be rarely seen on the pictures because Yang Yang warms them between her large paws most of the time.
“Their fluff gets more every day and one can already make out the black and white marking and the sound of their contented noises when they are being suckled, or cleaned, can be heard quite clearly over the speaker.”
The twins will be kept safely in their breeding box, out of sight from visitors, until they are around four months old.
It is only then that the youngsters will make their first excursions to the indoor enclosure, where members of the public will be able to see them.
Schönbrunn Zoo encourage anybody who wants to keep up with the twins to follow their social media accounts, where videos from the breeding box will be published.