The "genius chimpanzee" Ai, who came to Japan from West Africa in 1977, has died at the age of 49.
According to Kyoto University, she died of old age and organ failure, surrounded by staff and caregivers.
Ai was said to have been of great importance to research into primate intelligence. Over the years, she learned both the English alphabet and over 100 kanji characters. She was also able to identify several colors and use Arabic numerals.
The chimpanzee was said to have enjoyed painting and drawing. In captivity, she gave birth to a son, Ayumu, who has also attracted attention for his remarkably good memory.
In recent years, research experiments on chimpanzees and other primates have increasingly attracted criticism from both researchers and animal rights activists.
