The female calf - who remains without a name - was born on 12 November, and after a 15-month pregnancy, keepers at the zoo had been eagerly awaiting the new arrival.

But they were caught unawares when the birth happened right in front of their eyes, with the entire event caught on camera.

"It's quite unusual for a rhino to give birth in daylight hours," Emma Evison, rhino team manager, said.

"To be able to witness the calf safely entering the world, in front of our very own eyes, was just the most incredible privilege."

She said the calf is "very inquisitive and full of energy" and is "inseparable" with her mother Zuri.

"Little one is feeding regularly and already gaining in size and weight," Ms Evison said.

The eastern black rhino is classed as critically endangered by the International Union for the Conservation of Nature Red List, meaning it is facing an extremely high risk of extinction in the wild.

There are less than 600 found across Kenya, Tanzania and Rwanda, according to Chester Zoo.

Around 95% of rhinos in Africa have been wiped out by poaching, due to the demand for rhino horn, which stems from the traditional Asian medicine market, the zoo said.

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European conservation zoos hope that with projects like the endangered species breeding programme, the numbers of rhino in the wild will gradually increase.

There has already been some success with one group of zoo-bred rhinos re-located to a protected National Park in Africa in 2019, the zoo said.

"Our efforts to protect this magnificent species extend far beyond the zoo's boundaries and, while it's incredibly positive news that conservation efforts across Africa have led to a small recovery in rhino numbers, giving some much-needed breathing space, we know there's still lots of work to be done," Mike Jordan, director of animals and plants at Chester Zoo said.