Ai, the remarkable female chimpanzee celebrated for her extraordinary cognitive abilities, has died at the age of 49, Japanese researchers announced. Ai gained international recognition for her ability to recognize over 100 Chinese characters, Latin letters, Arabic numerals, and a range of colors, significantly advancing the scientific understanding of primate intelligence.

Her name, meaning “love” in Japanese, reflects the deep connection she formed with researchers during decades of study at Kyoto University’s Center for the Evolutionary Origins of Human Behavior. Ai’s work spanned perception, learning, and memory research, providing critical insights into primate cognition and the evolution of the human mind.

Ai passed away due to organ failure and age-related illnesses, according to the university. Tetsuro Matsuzawa, a leading primatologist who worked with Ai since 2014, highlighted her ability to accurately match Chinese characters with corresponding objects and colors. For example, when shown the Chinese character for “pink” alongside pink and purple squares, Ai consistently chose the pink square. She also demonstrated the ability to draw symbolic representations, such as using shapes to depict an apple.

Born in West Africa, Ai arrived at Kyoto University in 1977. In 2000, she gave birth to Ayumu, whose own skills became the subject of studies exploring knowledge transmission between parent and child chimpanzees. Ai’s extensive participation in research earned her the nickname “genius” in the media and made her the focus of numerous scientific publications, including studies in Nature.

Researchers at the Center emphasize that Ai’s curiosity and active engagement in experiments provided a foundational framework for understanding chimpanzee intelligence, offering valuable insights into the evolution of human cognition. Her legacy continues to influence studies of primate learning and memory worldwide.