Keo Memorial

Lincoln Park Zoo Bids Sad Farewell to Beloved Chimpanzee

Keo, 55, was one of the country’s oldest chimps

(Chicago, Sep. 30, 2013) -- Lincoln Park Zoo is deeply saddened to report that animal care staff made the difficult decision on September 30 to euthanize Keo, a geriatric male chimpanzee, after advanced cardiac disease compromised his quality of life. 

Keo was 55 years old. He was the oldest living male chimpanzee in any North American zoo. He arrived in Chicago in 1959 when he was just one year old and sired 11 offspring over the years.

“Keo was an incredibly special individual. He was truly a member of our family and will be missed dearly,” said Curator of Primates Maureen Leahy. “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.”

The median life expectancy for male chimpanzees living in zoos is 31.7 years. The maximum longevity record is 61 years.

For the final years of his life, Keo lived predominantly behind the scenes at Regenstein Center for African Apes with two female chimpanzees, Vicky, and her daughter, Kibali.

“Keo was always full of personality, even as his health began to decline,” said Director of the Lester E. Fisher Center for the Study and Conservation of Apes Steve Ross, PhD, who is the director of the Chimpanzee Species Survival Plan (SSP), “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.”

Lincoln Park Zoo works to conserve chimpanzees through research conservation efforts in Goualougo Triangle, Republic of Congo and Gombe National Park, Tanzania. Project ChimpCARE, headquartered at Lincoln Park Zoo, is aimed at addressing chimpanzee welfare and conservation concerns across the U.S. The zoo also supports the Chimpanzee Species Survival Plan which helps ensure that the chimpanzee population in zoos throughout the country remains healthy. 

Keo was a beloved individual and ambassador for his wild brethren. The Lincoln Park Zoo family is saddened by his loss. A memorial page has been set up in his honor, and Keo fans and friends of the zoo are welcome to leave comments, share memories, or express condolences to animal care staff who are especially affected by his loss. 

See Some of Our Favorite Keo Stories, Photos and Videos

Click here to download MPEG-4 video. (.MPEG, 68MB)
Click a thumbnail below to download full size version.



I was privileged to meet Keo during my brief time doing research at LPZ. He was quite the curious character who enjoyed looking at my painted toenails! My deepest sympathies go out to the keepers. I know your bonds with Keo were deep....he was family. :(

Sending thoughts of peace to all concerned.

Oh Keo. The world is a darker place without you. Thank you for all you taught me and all you were to many of the people I admire and respect. This isn't goodbye my friend, this is see you later.

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