Grass Valley resident shares memories of working with Koko, world’s most famous gorilla |

Grass Valley resident shares memories of working with Koko, world’s most famous gorilla

Mitzi Phillips signs the word "alligator" to Koko the gorilla. Phillips worked with Koko as a teacher and companion from 1983 to 1989.
Photo courtesy Mitzi Phillips

Mitzi Phillips has lived several more interesting lives than most of us.

She has been a dancer, a singer and an actress. She worked in disaster relief in the San Francisco Bay Area after the 1989 Loma Rica earthquake. She helped trace Holocaust survivors. She has written several murder mysteries, the most recent of which is about to be released on Amazon.

And for seven years in the 1980s, she worked as a teacher and companion to Koko, “The gorilla who talks.” Koko became a worldwide celebrity for her use of sign language and her near-human behavior such as crying over the death of her pet kitten. The western lowland gorilla died June 19 at age 46.

Koko was believed to have had an IQ between 75-95 (the average IQ for a human is 90-110) and could sign more than 1,000 words. She also understood spoken English.

Chance meeting

Born at the San Francisco Zoo, the gentle, nearly 300-pound ape began learning sign language as a baby in 1974 from Francine “Penny” Patterson as part of a Stanford University project.

Phillips, who now lives in Grass Valley, became fascinated by Koko while she was still at Stanford and followed her career through her move to the Gorilla Foundation established by Patterson in the Santa Cruz mountains. In her years with the foundation, Koko was featured in multiple documentaries and appeared on the cover of National Geographic twice.

Phillips lived nearby. One day in 1983, she spotted an ad in the small local newspaper that changed her life. The foundation, it seemed, was looking for an assistant who knew sign language.

Phillips gathered her courage and called the number on the ad.

“I had no background in science,” she explained. “I had studied music and theater.”

Phillips recalled with a laugh that she explained all this to the woman who answered the phone, then asked her how she could reach Patterson.

Can we get along?

Of course, it was Patterson herself who answered the phone. The researcher said she wanted to expose Koko to different disciplines, and an actress would be perfect for the job. But, she told Phillips, she had one major hurdle to overcome.

“Koko has to like you,” Patterson said.

After Patterson advised her to bring a present, Phillips picked out a filmy pink scarf for Koko. Koko first put it over her head, signing “all pink.” She next wrapped it around her arm, pretending it was a bandage, and then around her waist, signing the word “belt.” When it came time for Phillips to go, Koko tried to keep her there, making up a “story” that there was a red alligator under the trailer. “I guess that means you got the job,” Patterson told her.

Phillips worked with Koko until 1989.

“I was her teacher and companion — and, I hope, a friend,” she said. “We played games. I taught her songs. We had a wonderful time.”

A voice for the voiceless

It wasn’t all fun and games, of course. While they worked to keep Koko engaged and entertained, Phillips and other assistants kept meticulous log books that recorded all their interactions with Koko and the types of sign language words she used and in what context.

“She as very mischievous,” Phillips recalled. “And she did not know her own strength.”

Early on in her association with Koko, Phillips learned this the hard way. The gorilla signed that she wanted to play tug of war using a piece of rope passed through the wire mesh between the two.

“I foolishly thought I could win,” Phillips said, adding that she had looped the rope around her wrist. With one pull, Koko jerked her off her feet.

Phillips said she often forgot Koko was a gorilla, adding, “One thing we liked to do together was look through fashion magazines.”

“She loved for me to make up stories for her,” Phillips said.

One such interaction was carefully recorded.

“Do you want me to tell you a story?” Phillips asked the gorilla, who responded by signing, “Good.”

“What do you want it to be about?”

“Alligator,” Koko signed.

“Once there was an alligator who was very hungry. He said, ‘I will go and get some ice cream.’ On his way he met a — what did he meet?” Phillips said.

“Bird,” signed Koko.

The story, with help from Koko, ended with the ice cream man refusing to give the alligator any ice cream — but his friends, including the bird, share their food with him.

Often, Phillips said, Koko would combine words while signing to describe an object she did not already have a word for — “finger bracelet” for ring, or “stuck metal” for a magnet.

“It was really quite remarkable,” she said.

But, Phillips insisted, Koko was not an extraordinarily intelligent ape.

“She was just your average gorilla,” she said, adding they are all capable of communicating at that level.

The best place for gorillas is safely in the wild — but the reality is their habitat needs to be protected, Phillips said. Koko helped with that fight because she made it important to the world, she added.

“We can work to save habitat for animals, but it’s pointless unless we educate future generations about the value of those animals, that they deserve respect,” she said.

“Koko sparked the imaginations of thousands,” Phillips mused. “Most animals can’t speak for themselves — but Koko could.”

Contact reporter Liz Kellar at 530-477-4236 or by email at

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