When Auntie Rose died in early 2007, she was the oldest wild chimpanzee known to humankind. At around 63 years old, she was very elderly for a chimp, and her final months had been difficult. “She had lost all her body hair, and she just crawled about in the forest,” recalls Emily Otali, field director of the Kibale Chimpanzee Project in Uganda and a National Geographic Explorer. “I felt sorry for her.”

Still, until the very end, Auntie Rose had been fending for herself. Adult chimpanzees rarely share food, not even with the old-timers, so elderly animals have to keep up the effort required to find their own meals. Aging animals in the wild are less active,