The Gorilla Foundation says she died in her sleep at the organization's preserve in the Santa Cruz Mountains of Northern California.
Koko was born Hanabi-ko (Japanese for "Fireworks Child") on July 4, 1971 at the San Francisco Zoo.
Israeli warplanes strike Hamas positions in Gaza
Around two million people live in Gaza, majority the stateless descendants of refugees from what is now claimed to be Israel. At least 132 Palestinians have been killed since mass protests broke out along the Gaza border on March 30.
Koko, the beloved gorilla that learned to communicate with humans and then stole their hearts, has died. Koko was the subject of several other documentaries, including 2016's "Koko: The Gorilla Who Talks to People".
Koko appeared on the cover of her first National Geographic in 1978 and featured a picture she had taken of herself in the mirror.
"Betty met Koko in 2004 and became best friends nearly immediately", says the description of their meeting on The Gorilla Foundation's website.
Boat Caught in Europe's Migration Spat Brings Hundreds to Spain
The migrants were met by emergency workers, health officials, Red Cross volunteers and psychologists at the city's marina. The warmer weather has caused a spike in migration from North Africa to Europe.
The Gorilla Foundation announced on Twitter that it was "sad to announce the passing of our beloved Koko". In 1976, she founded The Gorilla Foundation, a nonprofit devoted to protecting gorillas.
She hung out with Williams in 2001, and when her caretakers informed her of his 2014 death, she seemed to be visibly upset. The second, in January 1985, included the story of Koko and a kitten, All Ball, that lived with her. Patterson's book Koko's Kitten followed the magazine article's publication. She was said to enjoy many TV shows and movies, including "Golden Girls" and "Pretty Woman". Dr. Patterson explained that 'we have lost a dear friend, Robin Williams.' Koko was quiet and looked very thoughtful. MORE: Watch Koko the gorilla rock out on the guitar She was an icon for inter-species communication and empathy.
Taylor Swift's 7 Stylish Looks to Follow
On the 1989 tour, she was constantly donning the skater skirt and jazzing it up with an assortment of crop tops and sports coats. She attended her first Academy of Country Music Awards just five months before her first album was released, that was in 2006.