‘Genius Bonobo’ Kanzi, Famous For Understanding Spoken English, Dies

The bonobo Kanzi, the undisputed ape language superstar who lifted the veil between the human and nonhuman worlds in meaningful two-way conversations, has died. He was 44.

Kanzi died Tuesday, March 18, 2025, at his home on the 230-acre Ape Initiative campus outside Des Moines, Iowa, where he and his family of bonobos had lived for more than two decades. The Ape Initiative said the cause of death is most likely heart disease, for which Kanzi was undergoing treatment. A necropsy will be performed.

Kanzi had the linguistic abilities of a 3-year-old child, knew hundreds of words, and used them in combinations, suggesting a capacity for symbolic thinking, previously thought to be an exclusively human capability. He was an accomplished toolmaker.

The bonobo also showed his cognitive abilities in everyday activities people in homes all over America might indulge in, such as painting and music — though Kanzi brushed shoulders with rock stars like Peter Gabriel and Paul McCartney. He played arcade games such as Pac-Man most of his life, and as an aging elder ape, beat the final boss in Minecraft. His true super-stardom, though, was rooted in how he could do those things.

The light in his chestnut eyes reflected a soul as deep as the cosmos, a being who was but a whisper away from his hominid kin.

“When you look into the eyes of an ape, you see the universe,” the renowned comparative psychologist Dr. Duane Rumbaugh, “the father of ape language research,” once told Al Setka, the former communications chief at the scientific organization that brought Kanzi and his family to Iowa in 2004.

“That was certainly true with Kanzi, and some of us were fortunate enough to spend a little time in that orbit,” Setka wrote on his Facebook page Wednesday.

What the world learned from Kanzi and his younger sister, Panbanisha, a language superstar in her own right, can never be repeated. Today, research that requires taking babies away from their mothers, no matter the value of the discovery, can’t overcome ethical obstacles. It was a different world in the 1980s when Dr. Sue Savage-Rumbaugh applied her lifelong fascination with how children acquire language to her work at the Language Research Lab at Georgia State University, where Kanzi and his family lived at the time.

Her discovery was elegant in its simplicity: Bonobos, like humans, acquire language simply by being exposed to it.

Savage-Rumbaugh had been attempting to communicate with Kanzi’s adoptive mother Matata, a wild-born bonobo, using lexigrams — a symbol-based vocabulary of hundreds of words — when young Kanzi picked up the symbol board and spontaneously asked for something to eat.

In the years that followed, the findings of the Rumbaughs and others, including scientists and researchers from around the world, filled dozens of books and scientific papers that challenged and upended previous assumptions. Kanzi and Panbanisha were featured in National Geographic, Smithsonian and other magazines with a scientific bent, as well as by national and international print, digital and broadcast news outlets. He was rightly called the “ape of genius.”

The scientific world lost a brilliant collaborator in Kanzi, according to Dr. Jared Taglialatela, the director of the Ape Initiative, an associate professor at Kennesaw State University and a research partner with Kanzi since he was a graduate student.

“Kanzi’s contribution to our understanding of what it means to be human, and our place on this planet, cannot be overstated,” Taglialatela told Patch. “Kanzi was an absolute treasure, and he will be sorely missed by everyone whose life he touched.”

Indeed, Kanzi’s name means “treasure” in Swahili, one of the languages spoken in the Democratic Republic of Congo, the only place on Earth where bonobos are found in the wild. He was an ambassador for the so-called “forgotten” or “hippie” ape, introducing the world to the delightful idiosyncrasies of bonobo society.

“He taught us so much about ourselves — and helped introduce bonobos to the world,” Taglialatela said. “Kanzi brought joy to everyone who had the privilege of meeting him.”

We humans in Kanzi’s sphere — scientists and researchers, caretakers and special friends, and people like Al Setka and me, who got to add a section on our resumes under “cool stuff I got to do” — lost a good friend, colleague and, importantly, teacher.

I was a reporter in Des Moines in 2006 when I met Kanzi for a magazine article that led to a three-year stint doing communications work for the Ape Initiative’s predecessor, Great Ape Trust of Iowa.

Whether he would grant me an audience — and Kanzi was very much like a king holding court — wasn’t assured. The audition included a selfie. If Kanzi liked it, we’d go from there. What if he rejected me in the bonobo version of “swipe left”? How humiliating would that be? I was more nervous about this interview than any before or since.

“Everyone who comes into his world is a slave,” William M. Fields, a researcher who worked with Kanzi for many years, said at the time. “He is the star. He is the last emperor; you are the serf. He is the elite; you are not.”

I did get the “interview.” The assessment he was royalty was spot on. I obligingly pretend-chased and tickled staff members, aware of how silly we would look to anyone who just happened by.

All visitors go through these machinations to prove they’re comfortable enough in their skin to be in the bonobos’ presence. Even Anderson Cooper had to wear The Bunny Suit, which earned the capital letters because the bonobos took great delight in cajoling random people into prancing around in the aging fleece costume that was beginning to look like it was molting.

Kanzi didn’t make it easy. He played the ever-temperamental rock star whose Perrier mineral water — an indulgence he enjoyed — was too warm, alternatively dismissing me and testing me with powerful displays of aggression. Just when I felt I had broken through, he would pound on the gorilla glass between us with so much force I thought it would shatter. And then it was back to chasing Setka around the bonobo lab lobby. I genuinely worried the behind-the-scences story everyone in the city wanted would fall flat.

Panbanisha saved me from professional humiliation. This is not a surprising development, given that females run the show in the matriarchal bonobo culture, forming strong bonds to manage male aggression.

I was invited to join her on a walk in the forest with Liz Pugh, Savage-Rumbaugh’s sister and Panbanisha’s lifelong best friend, human or non. In one astonishing moment after another, the already small 1.3 percent difference in our DNA melted away.

The gentle, easy way they had with one another was an epiphany. They seemed to have crossed over into a parallel universe, a world that was not quite bonobo, but not quite human, either. They were negotiating a campfire to roast marshmallows — a risky choice because she already was in trouble with the fire department, I pointed out from my vantage point, about 10 feet away. Panbanisha had just gained international attention for intentionally pulling the fire alarm not once but twice, a sophisticated stunt to get attention that was more effective than other forms of aggression.

She conceded I was right, Liz told me after they’d emerged from their secret world. We found a clearing. Panbanisha gathered the kindling and arranged it just right for a good fire. She threaded the stick with marshmallows, roasted them perfectly, daintily dabbed her mouth with a napkin after each gooey bite, and then turned to me with veiled eyes that commanded more than asked, “Did you see that?”

That gesture and the unspoken question it conveyed — Was I intuitive and smart enough to keep up? — unleashed a fascination about great ape and bonobo culture that, in turn, earned me a passport into their world. Kanzi, despite having made me work for every insight into his brilliant mind, became a dear friend and Panbanisha, a soul sister.

Beguilingly manipulative, the bonobos always had the upper hand, whether it was Panbanisha refusing to show off her skills to visiting media unless someone fetched her “candy coffee,” the lexigram symbols she used to order caramel macchiato from Starbucks, or Kanzi insisting that a reporter, or anyone courting his favor, put on The Bunny Suit.

The bonobos, quite simply, taught me my place in the world. Their kinship and friendship were humbling and liberating, implied permission to let go of manmade hierarchies and artificial systems.

Dr. Rumbaugh had been right. I saw the universe through different eyes.

The Ape Initiative said Kanzi was “his normal, happy self” Tuesday. He foraged for his breakfast and romped with his great-nephew Teco, then lay down after a grooming session with nephew Nyota. His heart stopped as he slept, the tranquil kind of passage we all hope for, but a transition especially befitting a type of great ape generally believed to be peaceful and cooperative.

As sad as Kanzi’s death is for those of us who loved and respected him, it’s a reminder to bridge our differences as a bonobo would, peacefully, cooperatively, and without aggression and conflict.

The world could use more bonobo right now.

Editor’s note: Beth Dalbey was a writer and editor for the former Great Ape Trust of Iowa’s communications department from 2007-2010.