Jane Goodall worked into her 90s. Here are 5 lifestyle habits that might explain how she stayed 'fit as a fiddle' for so long.

• Jane Goodall, world-renowned primatologist and conservationist, has died at 91. • She followed a plant-based diet, enjoyed learning new things, and was working right up to her last days. • Here are several lifestyle habits that might have helped her stay healthy and active for so long.

Jane Goodall, world-renowned ethologist and conservationist, has died of natural causes in her sleep while in Los Angeles for a speaking tour. She was 91.

Widely regarded as the world's foremost expert on chimpanzees, she transformed our understanding of primates when she documented their ability to use tools, challenging the long-held belief that only humans were capable of such innovation.

In later years, her work expanded to include environmental conservation, animal protection, and human rights.