5 June 2023

Koko the chimpanzee has celebrated reaching the milestone age of 50 at Whipsnade Zoo. 

The conservation zoo’s oldest mammal marked her incredible half-century on Sunday 4 June while tucking into a smorgasbord of her favourite foods - including gem lettuces and cherry tomatoes - before playing in the spring sunshine with younger chimps Phil, Grant and Elvis.  
Whipsnade Zoo primate keeper Grant Timberlake said Koko still has the energy of a young chimpanzee, despite outliving the average chimp by more than a decade: “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,” Grant said.  
Born at Dudley Zoo, Koko moved to London Zoo when she was nine, before heading to the UK’s largest zoo aged 33. 17 years later, Koko has joined the ‘Golden Club’ at the conservation zoo, alongside Gladys the flamingo - the zoo’s oldest animal - who will turn 53 in July.  

Gladys the flamingo at Whipsnade Zoo

Grant added that chimpanzees have incredible memories and explained that Koko had lived through some major wildlife milestones while living at ZSL’s two conservation Zoos - as well as contributing to an important conservation project for her species.  
“In the past 50 years, Extinct-in-the-Wild Pere David’s deer from Whipsnade Zoo were successfully reintroduced back to China, the late Queen Elizabeth and Prince Philip opened the Centre for Elephant Care at Whipsnade and ZSL camera-traps captured the first ever photos of chimpanzees at Douala-Edea National Park in Cameroon,” he said. 
“Koko herself has voluntarily contributed to an important conservation project for her species, helping to improve and protect the health of chimpanzees around the world: our veterinary team work closely with the chimpanzees at Whipsnade Zoo, training them to use finger monitors so the team can gather ECG readings, as well as allowing vets to conduct ultrasound examinations on their hearts.”  

Koko the chimpanzee at Whipsnade Zoo

This critically important data is shared with the Great Ape Heart Project, an international organisation working to investigate and understand the issue of cardiovascular disease in great apes. The project works to create a centralised database on great ape heart health, fuelling important research projects, as well as ensuring the primates receive the best possible care at conservation centres around the world.  
“Like a lot of humans when they get older, Koko has developed mild arthritis in her hands, but thanks to the care she receives, it hasn’t slowed her down at all,” Grant added. “Our vet team treat the inflammation with soothing, low level laser treatments – a simple but effective way to help her remain pain-free and fully mobile. We hope to celebrate many more birthdays with Koko at Whipsnade Zoo.” 
Visitors can see Koko and the rest of the chimpanzee family, as well as 10,000 other animals at Whipsnade Zoo this June. 

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