A 13-year-old Eastern black rhino, Ema Elsa, finally gave birth to the male calf after a 15-month pregnancy at Chester Zoo.

The incredible moment was caught on camera on Saturday night and in just one hour, the video has been watched more than 16,000 times on the Zoo's Facebook page.

Tim Rowlands, curator of mammals at Chester Zoo, called the birth "another perfect delivery" from Ema Elsa, who has also given birth to Bashira and Chanua at the zoo.

After the calf lands safely onto deep sand at 10.54pm, attentive mum Ema Elsa can been seen licking her baby's forehead before it struggles to its feet just 20 minutes later.

Video captured the next morning shows him happily wandering around the enclosure as his mum tucks into hay from her feeding station.

The new calf's dad is 31-year-old Kifaru who arrived at Chester Zoo in 2014 from Hannover Zoo in Germany. This new arrival - who will be named by keepers - is his first at the Zoo and he is also dad to Samira, Saya and Taco

Fewer than 650 black rhinos are believed to be left in the wild in Africa. Chester Zoo - which is now home to 10 - is part of the European Endangered Species Breeding Programme.

Rhino horns have a street value of more per gram than gold or cocaine and are highly prized by illegal poachers because of the demand from the traditional Asian medicine market.

Mr Rowlands said: "These animals are on the very brink of extinction and our new arrival is hugely important to the conservation of the species.

"Ema Elsa is an experienced mum. She has given birth twice before at the zoo and this was another perfect delivery.

"It's important now that she and her new calf have some quiet time together to strike up those vital early bonds."