Koko the Gorilla
Koko the Gorilla

Koko, the female western-lowland gorilla who was made famous by the video of she interacting with actor Robin Williams, is no more.

The Gorilla Foundation – built around Koko and her fame for the betterment of the species – announced her death on Thursday, June 21. They said in a statement that she died on Tuesday in her sleep. She was aged 46, with her birthday coming up next month.

"Koko touched the lives of millions as an ambassador for all gorillas and an icon for interspecies communication and empathy. She was beloved and will be deeply missed," said the foundation in its release.

Soon after, the Twitter handle associated with Koko quite fittingly posted two words she had learnt and used: "Very sad." The message was followed by an appropriate emoji.

The website dedicated in her name – koko.org – crashed on Thursday evening as news spread of her demise.

Who was Koko?

Koko was one of the few apes across the world who reportedly learnt to communicate through a modified version of the American Sign Language and understood around 2,000 words in English.

Koko as cared for throughout her life by Francine "Penny" Patterson, who received the simian as a loan for her doctoral studies. She ended up living under Patterson's care, learning sign language and being exposed to English at an early age.

Koko the Gorilla
Koko the Gorilla

The first signs of fame for Koko came from news reports that talked of how she demanded a cat for a pet in the early 1980s. She was unhappy when given a lifeless plush toy, and thus received her first cat on her birthday in 1984. Interestingly, she chose her first "pet" from a litter of kittens and named it "All Ball."

Sadly, All Ball was killed in an accident later in the year, and Koko is believed to have made signs to express sadness and crying to Patterson. She would go on to have other kittens.

Her other great love was for water baby dolls, and she would love getting a new one each time.

Brushes with celebrities

Koko met several celebrities over the years, with the encounters documented well on video. The most recent of these celebrities was musician Flea last year, but definitely the most famous was actor Robin Williams, who met her in 2001.

Williams would call the encounter, where Koko – among other things – took off his glasses and tried them on and even identified him on a VHS tape cover, called it a "mind-altering experience."

In a video released in 2014 by the official YouTube channel associated with Koko, she is seen asking Williams to tickle her multiple times.

The text accompanying the video -- released in memory of Williams after he ended his life in 2014 – said Koko signalled she was sad when told of his passing.