Kanzi has died at the age of 44. The iconic bonobo reshaped our understanding of ape intelligence, challenging long-held beliefs about what separates humans from our closest living relatives.
Kanzi passed away in Des Moines, Iowa, on March 18 at the age of 44, according to the Ape Cognition and Conservation Initiative, a research group dedicated to the study and preservation of bonobos. His handlers are still awaiting autopsy results, but he seemed fine on the day he died, chasing a fellow bonobo through the enclosure, foraging for food, and partaking in some grooming. That said, the elderly Kanzi was being treated for heart disease. Life expectancy for bonobos is around 40 years, so his death isn’t entirely unusual or unexpected.
“Kanzi means so much to so many people. Our team is absolutely devastated by Kanzi’s passing,” the Ape Initiative said in its statement. “A favorite among his bonobo family members, Kanzi was a friend to everyone.”
Kanzi is truly a legend among great apes—a group that includes chimpanzees, bonobos, gorillas, orangutans, and humans (yes, you’re a great ape). His proclivity for language and toolmaking, along with his clear zest for life, establishes him as one of the most important nonhuman minds we’ve ever studied—and he had a profound influence on my own intellectual path.
Born in captivity in 1980, Kanzi was initially raised at the Yerkes Field Station in Georgia, part of what is now known as the Emory National Primate Research Center. Kanzi, at the age of five, along with his sister Panbanisha, were relocated to Georgia State University’s Language Research Center. From there, the pair ended up at the Great Ape Trust in Des Moines, Iowa—a facility that would later become mired in controversy; the center shut down following Panbanisha’s death in 2012 amid allegations of animal mistreatment and internal dysfunction. The site got a second life in 2013 when the Ape Initiative stepped in to take over operations.
Koko the gorilla and Washoe the chimp communicated via sign language, but Kanzi took communication to a new level, demonstrating a profound capacity to communicate via symbols and comprehend verbal English.
A key Kanzi caretaker, primatologist Sue Savage-Rumbaugh, guided him through his development using a keyboard labeled with geometric symbols known as lexigrams. Working at the Great Ape Trust, Savage-Rumbaugh claimed that Kanzi eventually learned the meaning of around 3,000 spoken words.
In the 1990s, archaeologists Nicholas Toth and Kathy Schick from Indiana University worked closely with Kanzi, teaching him how to make and use stone tools using techniques borrowed from early humans. Over time, Kanzi didn’t just copy their methods—he started developing his own way of flaking stones, offering rare insight into the cognitive and motor skills required for prehistoric toolmaking.
While at the Great Ape Trust, Kanzi and his fellow apes enjoyed a facility equipped with drinking fountains, hydraulic doors they could operate themselves (humans had to buzz to get in, with the apes acting as gatekeepers to their own facility), a kitchen stocked with a vending machine and microwave oven, and even a rec room complete with a TV and VCR. Kanzi was known to enjoy the Clint Eastwood film Every Which Way But Loose (featuring the orangutan Manis), along with Quest for Fire and Greystoke: The Legend of Tarzan, and Babe.
Famously, Kanzi was also a gamer. I first learned of Kanzi in 2006 when I spotted a bootlegged NHK Youtube video showing a bonobo playing Pac-Man with both proficiency and delight. I corresponded with Savage-Rumbaugh about the video, and she told me: “This film is so compelling and there is so much of it (over 300 hours) in so many different natural circumstances, that any thought that these clips represent anything other than their real competencies, become unreasonable.” For me, the experience proved to be life changing, setting me on course to pursue more work in animal rights activism and promoting the notion of nonhuman animal personhood.
Later, Kanzi would likewise show a keen interest in Minecraft, as chronicled by YouTuber Christopher Slayton in 2023. Speaking to the Des Moines Register, Amanda Epping, a research coordinator at the Ape Initiative, said Kanzi loved the video game and enjoyed having a crowd that cheered for him. “It’s fun for him, it’s mentally stimulating,” said Epping, adding that Kanzi’s “ability to learn new skills within minutes of us showing him was truly incredible, he could understand what needed to be done in Minecraft within just a few attempts of the task.”
Kanzi was more than a scientific curiosity, as the comments from the Ape Initiative attest. He was living proof that the artificial boundaries we draw between human and nonhuman intelligence are flimsier and far blurrier than we thought. Looking back at Kanzi and his extraordinary life, it’s clear that the gap between humans and our fellow apes isn’t as wide as we’d like to pretend.
