Amazing Facts About Koko, The Celebrity Gorilla Who Knew Sign Language

Koko was a famous gorilla who made a huge impact on the way researchers understand her species. Her intelligence exceeded their expectations as she was able to sign thousands of words, paint, play an instrument, express empathy, and more. Read on to learn more about what made Koko a truly remarkable animal.

She Was Able To Express Empathy

koko-1
Barney Peterson/San Francisco Chronicle via Getty Images
Barney Peterson/San Francisco Chronicle via Getty Images

Being able to feel for another individual is a very complex emotional skill that not all mammals seem to possess. One of the amazing things about Koko was her ability to express empathy.

There is a heartwrenching scene in the movie Tea with Mussolini where a boy leaves his family. When watching it, Koko’s eyes would water and she would sign the words “sad,” “cry,” “trouble,” and “mother,” showing that she could feel for others.

She Could Play The Recorder

koko-17
BBC
BBC

One of the most impressive tasks that Koko was able to do was playing an instrument. She learned how to play the recorder. Before Koko, experts didn’t think that gorillas could learn such an intricate task.

Not only did playing prove that Koko could do something so complex, but it more specifically showed she could regulate her breathing. Wind instruments require the player to release air in a certain way, and Koko was intelligent enough to understand that.

She Could Paint And Judge Paintings

koko-18
PBS
PBS

Koko and her male counterpart, Michael, were both able to paint. Though some paintings were more abstract, they weren’t just arbitrary brush strokes. The gorillas would often create images of things in their environment.

If that wasn’t impressive enough, they also knew how to judge their paintings. The ones they didn’t particularly like they would respond to by signing “toilet.” Some of the more impressive paintings are still for sale at the Gorilla Foundation’s website.

Koko “Adopted” A Kitten

koko-7
BBC
BBC

Koko loved kittens and was a fan of The Three Little Kittens and Puss ‘n’ Boots. She asked her caretakers for a pet kitten, and so they gave her a stuffed one.

Koko signed “sad” in response to the stuffed animal, suggesting she wanted a real-life kitten. Her caretakers got the hint and let her pick out one from a litter. Koko named the cat All Ball and treated it like she would a baby.

She Made Up Phrases And Sounds

Getty Images
Getty Images

Koko not only learned sign language, but she was also able to create her own forms of communication. Aside from making the typical gorilla sounds like grunts and purrs, Koko would also create vocalizations that were unique to her.

She also knew how to describe something she didn’t yet have the word for. When Koko didn’t yet know how to sign the word “ring,” she signed the words “finger” and “bracelet.” These descriptions illustrated Koko’s impressive level of understanding.

Her First Words Were Related To Eating

Jerry Telfer/San Francisco Chronicle via Getty Images
Jerry Telfer/San Francisco Chronicle via Getty Images

Getting enough to eat and drink is one of the biggest things on an animal’s mind, so it’s not much of a surprise that all of Koko’s first words were related to diet.

The first words that Koko was able to sign successfully were “more,” “food,” and “drink.” Many pets communicate these desires to their owners all the time in their own ways. Through interspecies communication, animals can more precisely convey their needs to their caretaker.

She Understood Mortality

koko-14
Peter Breining/San Francisco Chronicle via Getty Images
Peter Breining/San Francisco Chronicle via Getty Images

One thing that sets humans apart from many other mammals is our awareness of mortality. Koko proved that she also knew that creatures would cease to exist. When shown a skeleton, Koko was able to indicate through sign language that it was dead.

The gorilla was then asked where the skeleton would go, to which she signed, “A comfortable hole.” Koko even gave a kiss goodbye, showing that she understands that the deceased are gone.

Penny Was Koko’s Caretaker For Decades

koko-6
Peter Breining/San Francisco Chronicle via Getty Images
Peter Breining/San Francisco Chronicle via Getty Images

Koko was just one year old when researcher Francine “Penny” Patterson took the gorilla under her wing. Penny approached the San Francisco Zoo to ask them to use Koko for a Ph.D. thesis.

The zoo agreed under the stipulation that Penny commit to caring for Koko for at least four years. Penny ended up remaining Koko’s caretaker for the remainder of the gorilla’s life! Penny was able to teach Koko around 2,000 words over the decades.

Koko And Her Companion Signed To One Another

koko-20
Marcos del Mazo/LightRocket via Getty Images
Marcos del Mazo/LightRocket via Getty Images

Koko and her companion Michael didn’t just sign for researchers. They also communicated with one another through sign language. One breakthrough moment was when Michael relayed his memory of his mother’s death to Koko.

Michael’s mother was killed by poachers, so his ability to recall the event was a huge stride in the fight to prevent illegal gorilla hunting. The Gorilla Foundation takes in orphaned gorillas and helps protect the species through education and research.

Robin Williams Helped Koko Mourn Her Companion

koko-robin-williams
BBC
BBC

One thing that illustrated Koko’s advanced emotional capacity was her ability to grieve the loss of others. When her companion Michael passed, the gorilla experienced loss of appetite and she even stopped smiling.

Comedian Robin Williams visited Koko around this time and his lighthearted presence impacted Koko. He got her to laugh and play games again, which was a sign that her sadness could at least be kept at bay with the help of the friendly comedian.

Roses Were One Of Koko’s Favorite Foods

koko-19
PBS
PBS

Gorillas spend about half of their time foraging for food, so it was important that Koko get to experience this part of life. The Gorilla Foundation would create a sort of foraging game for Koko so she still had to work for the food they gave her.

She received seven meals each day, and each meal was a pound of plant-based food! One of Koko’s favorite foods was roses, along with carnations, plantains, and berries.

Her Communication Skills Rivaled That Of A Human Toddler

koko-13
Getty Images
Getty Images

Koko’s communication skills have been compared to that of a three-year-old human. Likewise, the gorilla learned most of her vocabulary between the ages of two and five.

Though she wasn’t able to grasp grammar and syntax, Koko did understand thousands of words that made it possible to have a back and forth conversation with her. She was also able to help researchers teach sign language to her male counterpart, Michael, who developed a 600-word vocabulary.

She Helped Mr. Rogers Take Off His Shoes

Fotos International/Courtesy of Getty Images
Fotos International/Courtesy of Getty Images

Koko genuinely enjoyed watching TV. Some of her favorite movies were Free Willy, Doctor Doolittle, Maid in Manhattan, and Pretty Woman. She also loved Mister Rogers’ Neighborhood.

Koko was such a fan that when she met Mr. Rogers, she recognized him right away. The gorilla even helped Mr. Rogers take off his shoes because she remembered him doing that in the show! Moments like these showed that Koko was really absorbing all that she observed.

She Had A Safety Blanket

koko-9
BBC
BBC

Part of what made Koko such a brilliant animal was her natural curiosity. The gorilla loved to play and was very active. Investigating things is how Koko learned more about them, even as a child.

Though Koko was very interested in learning more about the world around her, she was also naturally timid. When she went to a new location, Koko had to have her security blanket around as a sense of safety and comfort.

She Passed The Mirror Test

koko-11
Barney Peterson/San Francisco Chronicle via Getty Images
Barney Peterson/San Francisco Chronicle via Getty Images

Another way that Koko stood out was her ability to pass the mirror test. The test consists of putting an animal under anesthesia and marking them with paint or a sticker.

The mark goes on a spot that they wouldn’t be able to see without the help of a mirror. When the animal wakes up, they see the mark in the mirror. If they go to touch it on themselves, then it indicates a higher level of self-awareness.

Koko’s Fans Sent Her Birthday Cards

koko-10
BBC
BBC

One of the aims of The Gorilla Foundation is to spread awareness of these animals. In doing so, they create more empathy toward gorillas that encourages others to take care of the incredible species.

Koko was a fundamental part of this mission since her advanced skillset made her more relatable. The gorilla’s supporters were such big fans that they would sometimes send in cards and presents on Koko’s birthday! Knowing that Koko could feel complex emotions made the offerings all the more special.

She Could Reference Objects That Weren’t Around

koko-3
PBS
PBS

While animals can sometimes learn to recognize certain words, it’s often in reference to something nearby. Something that made Koko stand out was her ability to reference things that weren’t even around her.

This skill is called displacement and it isn’t common among animals. Koko’s ability to call to mind things that weren’t around greatly expanded the breadth of conversations that she could have. It was also an example of her memory and communication working together.

Her Name Means “Fireworks Child”

koko-4
Peter Breining/San Francisco Chronicle via Getty Images
Peter Breining/San Francisco Chronicle via Getty Images

Researchers didn’t just come up with the name Koko because it was cute. Koko’s full name is actually Hanabiko, which means “fireworks child” in Japanese. Koko was born on the 4th of July, a holiday that is known for its fireworks.

Her birth took place in 1971 at the San Francisco Zoo, where her parents Jacqueline and Bwana lived. Koko also had two brothers through which she has nieces and nephews who still reside in zoos around the US.

She Wanted To Be A Mother

gorilla-mother
Brian Lawless/PA Images via Getty Images
Brian Lawless/PA Images via Getty Images

Koko loved to treat visiting kittens like they were her own. She would even sign “baby” while holding the kitten. This made her caretaker, Penny, well-aware that Koko wanted to be a mother.

Though Koko grew up with fellow gorilla Michael, they never became more than friends. Koko did mate with a gorilla named Ndume, but she miscarried. Penny later told ABC News, “I think that’s one of Koko’s deepest regrets is not having a baby.”

Koko Referred To Herself As “Queen”

koko-8
BBC
BBC

Koko got to such an advanced level that she could use sign language to not only describe the world around her, but also herself. One of the first words Koko ever used in reference to herself was “queen.”

Her lifelong caretaker and teacher, Penny, surmised that Koko knew how unique she was due to all of the attention she got. Koko was too smart to not notice what an impact she was making, even if she didn’t exactly know how.