When researchers asked the gorilla what she wanted for her birthday, she signed her answer: a cat. Not food. Not toys. A kitten.
Koko was a western lowland gorilla born at the San Francisco Zoo in 1971. As an infant she became the subject of a remarkable language project led by researcher Dr. Francine “Penny” Patterson, who taught her a modified form of American Sign Language.
Koko went far beyond tricks. By the project’s count, she learned more than 1,000 signs and understood some 2,000 spoken English words. She combined signs into new meanings, joked, lied a little (she once signed that a kitten had ripped out a sink), and expressed sadness in ways that stunned the public.
All Ball, and the Kittens After
In 1983, Koko asked for a cat. Given a toy first, she signed “sad.” Then she was allowed to choose a real kitten from a litter; she picked a tailless grey male and named him All Ball.
She carried him gently, tried to nurse him, and played with him like a baby of her own. When All Ball escaped and was killed by a car the following year, Koko signed “bad, sad, bad” and cried out — grief, in any language.
Koko went on to care for other kittens over the years, and her bond with them became one of the most beloved animal stories in the world.
The Gorilla Who Spoke to Us
Koko met celebrities, appeared in documentaries, and did more than any single animal to convince the public that gorillas think, feel and form attachments. She died in her sleep in June 2018, aged 46, and was mourned worldwide.
❓ Q&A
Q: How many signs did Koko know? A: The Gorilla Foundation reported a working vocabulary of more than 1,000 signs, with understanding of around 2,000 spoken words.
Q: What was her kitten called? A: All Ball — a grey kitten Koko chose and named herself in sign.
Story compiled from widely reported accounts of Koko and the Gorilla Foundation.
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