The Lincoln Park Zoo put down its oldest male chimpanzee Monday after his long, full life became compromised by cardiac disease.
Keo, the 55-year-old chimp, was the first to live at the Lincoln Park Zoo after arriving in 1959. He was also the oldest living male chimpanzee in a North American zoo.
“Keo was an incredibly special individual. He was truly a member of our family and will be missed dearly,” Curator of Primates Maureen Leahy said. “His long, rich life is a testament to the wonderful care he received here as well as the veterinary advancements that have been made in the past five decades.”
Keo was plagued by an advanced cardiac disease that eventually worsened his quality of life, zoo officials said. He remained behind the scenes at the zoo during his final years.
“Keo was always full of personality, even as his health began to decline,” said Steve Ross, director of the Lester E. Fisher Center for the Study and Conservation of Apes. “I can speak for everyone who knew Keo when I say his loss is felt keenly, and working with him was a privilege that we will all treasure forever.”
To remember Keo, the Lincoln Park Zoo has set up a memorial page where fans and friends can leave comments and condolences.
Chimpanzees typically live around 32 years. However, Keo was still younger than the oldest living chimpanzee, which set a longevity record for 61 years.