Koko the gorilla has died

Koko, the gorilla that learned sign language and formed several celebrity friendships while in captivity in the US, has died aged 46.

The western lowland gorilla, who gained her fame by learning "gorilla sign language" died peacefully in her sleep at the Gorilla Foundation's preserve in California.

Originally named Hanabi-ko – Japanese for “fireworks child” – after being born at San Francisco Zoo in 1971, Koko learned a rudimentary sign language through a researcher. Koko reportedly understood around 2,000 words of verbal English.

Koko was the subject of numerous documentaries and also appeared on the cover of National Geographic.

“Her impact has been profound and what she has taught us about the emotional capacity of gorillas and their cognitive abilities will continue to shape the world,” the Gorilla Foundation said.