Whipsnade Zoo chimpanzee reaches 50th birthday
One of Europe's oldest chimpanzees has reached the milestone age of 50.
Koko was born at Dudley Zoo in the West Midlands in 1973 and has lived at Whipsnade Zoo near Dunstable, Bedfordshire, since 2006.
The oldest chimpanzee on the continent, the similarly-named Coco, celebrated her 58th birthday in April at Twycross Zoo in Leicestershire.
Chimpanzees in captivity generally live to about 33 years of age, according to the Press Association.
The oldest chimpanzee on record is Little Mama, who was thought to be in her late 70s when she died in a Florida safari park in 2017.
Grant Timberlake, primate keeper at Whipsnade Zoo, said Koko was in "brilliant health", but had mild arthritis in her hands.
She received low-level laser treatments that kept her "pain-free and fully mobile".
Koko has contributed to several important conservation projects for her species. Ultrasound examinations on her heart helped experts understand cardiovascular disease in great apes.
In 2007, Koko briefly escaped her enclosure with another chimpanzee.
She was recaptured but Johnnie, her fellow escapee, was killed due to the threat he posed to the public.
Koko is Whipsnade's oldest mammal, but Gladys the flamingo is the zoo's oldest animal - she will turn 53 in July.
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