I have heard of Koko a couple of years ago. Koko is a female gorilla born on July 4, 1971, in San Francisco, California. She has a website.
Koko uses sign language and understands spoken English. According to information on her website, she participated The Gorilla Language Project and became very successful:
During the course of the study, Koko has advanced further with language than any other non-human. Koko has a working vocabulary of over 1000 signs. Koko understands approximately 2,000 words of spoken English. Koko initiates the majority of conversations with her human companions and typically constructs statements averaging three to six words. Koko has a tested IQ of between 70 and 95 on a human scale, where 100 is considered "normal." Michael, the male silverback gorilla who grew up with Koko, had a working vocabulary of over 600 signs.
I feel the urge to remind you that any average American person today uses just about 250 to 500 words to communicate in everyday language.
Koko has a photo blog where you can see many images of her.
Koko is working with Dr. Penny Patterson:
Her teacher, Dr. Penny Patterson, began working with Koko as a Ph.D. project at Stanford, thinking it would only be a 4-year study.
Thirty-some years later, Penny and Koko continue to work together at the Gorilla Foundation in one of the longest interspecies communication studies ever conducted, the only one with gorillas. Koko now has a vocabulary of over 1000 signs, and understands even more spoken English.
When I had a look at Koko over Wikipedia, I came across with funny news:
Koko has been involved in several sexual harassment lawsuits. At least three female former employees have claimed that they were pressured into showing their breasts to Koko. They alleged that Patterson encouraged the behavior, often interpreted Koko's signs as requests for nipple display, and let them know that their job would be in danger if they "did not indulge Koko's nipple fetish." Koko has been known to playfully grab both male and female nipples without warning or provocation. Patterson claims that Koko uses the word "nipple" to refer to humans.
All claims of harassment have been permanently dropped as of November 21, 2005 after the foundation and the parties involved reached a settlement.
Jody Weiner, Koko's lawyer, writes about Koko and sexual harassment in the book Kinship With Animals.
Nevertheless, it is interesting to see an intelligent gorilla. Koko, without doubt, is more intelligent than many people in this world.