In Japan, a female chimpanzee named Ai passed away on January 9, 2026, due to old age and organ failure. She had lived at the Kyoto University's Center for the Evolutionary Origins of Human Behavior since 1977 and was well-known for her remarkable cognitive abilities. Over the years, Ai participated in numerous research studies aimed at understanding the chimpanzee mind, especially her capacity for memory and learning. Ai was born in western Africa and quickly became a vital part of the Ai Project, a research initiative dedicated to understanding cognitive functions in chimpanzees. Researchers recognized her cognitive skills early on and equipped her with a special keyboard linked to a computer at just 18 months old. She demonstrated a significant ability to use symbols, mastering numerical naming from one to six and identifying 300 types of objects by name and color by the age of five, as highlighted in a scientific paper published in 1985. These findings contributed to a greater understanding of primate cognition. Aside from her participation in cognitive tasks, Ai was also known to engage in creative activities such as drawing and painting. She would use marker pens on blank paper purely for enjoyment, without any food incentives. Interestingly, Ai exhibited remarkable behaviors outside of her research environment, including a memorable incident where she escaped her enclosure with the help of another chimpanzee, showcasing her cleverness and problem-solving abilities. In 2000, Ai gave birth to a son named Ayumu, who has also gained recognition for his impressive memory capabilities. As a significant figure in the field of primate research, Ai’s legacy was celebrated, particularly during the 40th anniversary of the Ai Project in 2017. A scarf created from one of her paintings was gifted to renowned primatologist Dame Jane Goodall, symbolizing the impact of Ai's contributions to our understanding of the cognitive abilities of chimpanzees and the emotions that bind humans and primates alike. Ai's passing marks the end of an era in cognitive research, leaving behind a lasting influence on the study of primate intelligence.