A CHIMPANZEE born at Dudley Zoo, believed to be one of Europe's oldest, has celebrated her 50th birthday.

Koko, who was born at Dudley Zoo in 1973, reached the milestone on Sunday - having outlived a chimpanzee's average life expectancy by more than 10 years.

Chimpanzees in captivity generally live to around 33 years of age, but they have been known to survive long into their 60s.

Koko spent her first nine years in the Black Country before being moved to London Zoo when she was nine. She was later transferred in 2006 to Whipsnade Zoo in Dunstable, Bedfordshire, where she has lived ever since.

In 2007 she made headlines when she and a fellow chimpanzee briefly escaped from their enclosure.

Koko was recaptured and led back to the enclosure, but her fellow escapee, Johnnie, was shot dead due to the threat he posed to members of the public.

Whipsnade Zoo primate keeper Grant Timberlake said: "Koko might have just turned 50 but she's still in brilliant health, thanks to the dedicated care of our zookeepers and veterinary team.

"Particularly when she sees her favourite food, it's like she's 20 years young again - climbing and swinging as fast as she can through the trees to reach it."

Although Koko suffers from mild arthritis in her hands, this is soothed by low level laser treatments which keep her "pain-free and fully mobile".

Meanwhile, vets have carried out ultrasound examinations on her heart to understand more fully the issue of cardiovascular disease in great apes.

Koko's milestone makes her one of the oldest chimpanzees in Europe.

The current living record holder, called Coco, celebrated her 58th birthday at Twycross Zoo, Leicestershire, in April.

The oldest chimpanzee on record was Little Mama, who was thought to be in her late 70s when she died at a safari park in Florida in 2017.