Koko, the gorilla who gained international fame for her ability to communicate through sign language, passed away on June 19, 2018, at the age of 46. Her death led to a worldwide outpouring of sympathy and many reflections on her legacy. This attention, though, overshadowed a fierce legal battle over the fate of her companion, a gorilla named Ndume.

The fireworks child

Koko’s full name was Hanabiko, a Japanese word meaning “fireworks child,” a reference to her birth on the fourth of July in 1971. She was born in the San Francisco Zoo but spent most of her life at the Gorilla Foundation, a preserve located in the Santa Cruz Mountains. Early in her life, she was chosen, along with another young gorilla named Michael, to participate in a special program designed to teach gorillas to communicate through American Sign Language. That program was run by Francine “Penny” Patterson who had previously studied Koko as part of her doctoral research.

Koko came to international attention in 1978 when she was featured on the cover of National Geographic for her unique abilities. Over the years, her fame grew and she made a number of famous friends, including Leonardo DiCaprio, Mr. Rogers, Sting, and most memorably, Robin Williams. In fact, even years later Koko still remembered Williams and expressed sadness over his death in 2014.

A full life

Koko reportedly knew over 1,000 different signs. More importantly, though, she knew how to combine signs to create more complex language. She was even capable of using signs to invent new words. So, for instance, while no one ever taught her a sign for “ring,” she came up with her own expression, combining the signs for “finger” and “bracelet.”

She was also capable of communicating in meta-language, a sophisticated cognitive ability. Not only did she communicate, but she could communicate about communicating. For example, she might tell another gorilla “good sign” in response to something he said, an indication that she thought about what she was doing.

Additionally, she knew how to use language deceptively and could employ it for humor.

Her ability to sign, though, was perhaps more important for what it allowed her to reveal about the inner life of gorillas. Because she could sign, she was able to communicate her thoughts and feelings to her handlers, which provided us, as humans, with new insight into these magnificent creatures. For example, Koko famously had a pet kitten, named All Ball. After Ball was struck by a car and killed in 1984, Patterson asked Koko what had happened to Ball. Koko’s response: cat, cry, have-sorry, Koko-love. Finally, then, she added two additional signs: unattention, visit me. Such moments made clear that gorillas, primates, perhaps many animals, share with humans the ability to feel emotions like sadness, anger, loneliness, and joy.

Lingering scientific debate

Despite Koko’s fame for her ability to communicate, not all scientists saw her accomplishment in the same way. A controversy developed over just how much she actually knew. Part of this controversy stemmed from the fact that Patterson and others who studied Koko, seemed to seek a great deal of mainstream publicity but rarely published actual scientific papers on their subject. This led some to suspect that Koko’s accomplishments were not as impressive as they may have seemed.

In particular, some researches claimed Koko was not actually communicating in any real sense but rather had learned to mimic her handlers and to respond to what they expected. Some published papers argue that in videos taken of Koko “communicating” the handlers are essentially manipulating the conversation, prompting Koko to give the responses that they want or expect.

Koko’s passing

None of that controversy did anything to dim Koko’s immense popularity. When she died in June 2018, at the age of 46, the world mourned. “Legit bawling like a baby right now. This news just breaks my heart. From an early age, I was fascinated with Koko and she taught me so much about love, kindness, respect for animals, and our planet,” wrote one poster to the Gorilla Foundation’s Facebook page.

For its part, the Gorilla Foundation noted, “Koko touched the lives of millions as an ambassador for all gorillas and an icon for interspecies communication and empathy.” In the wake of her death, the foundation has promised to devote its time and resources to protecting silverback gorillas in Africa, where they remain an endangered species.

What to do with Ndume

In the meantime, Koko’s passing left a more pressing controversy. After her companion, Michael died in 1990, the Gorilla Foundation contracted with the Cincinnati Zoo for a replacement. That gorilla, Ndume, never learned to sign but he became Koko’s close friend, living with her in the foundation’s preserve for 27 years, until her death last year.

At that point, Ndume was left alone, a difficult position for a silverback gorilla who are naturally social animals. In addition, concerns were raised about conditions in the preserve, with PETA supporting the Cincinnati Zoo’s efforts to bring Ndume home and criticizing the foundation’s “tumbledown facility, with its history of failures in both cleaning and veterinary care.”

Despite the fact that the foundation had signed a legal agreement in 2015 that stipulated Ndume would be returned to Cincinnati when the time came to do this in 2018, they insisted that moving Ndume would endanger his life and possibly even kill him. Eventually, a judge disagreed and Ndume was finally returned to his original home in June of this year.

Initially, Ndume has been placed in an area on his own while he adjusts to his surroundings. A tarp has been draped over the viewing area so he would not be disturbed by human visitors, but zoo officials say that this barrier will gradually be removed. Holes will be cut in the tarp so that Ndume can peak out and eventually, it will be taken down completely.