(NEXSTAR) – Conservationist and preeminent chimpanzee expert Jane Goodall died at the age of 91, the Washington D.C.-based Jane Goodall Institute announced on Wednesday. Goodall was in California as part of her speaking tour and was scheduled to speak in Los Angeles Friday. The research organization said they learned Wednesday that "Dr. Jane Goodall DBE, UN Messenger of Peace and Founder of the Jane Goodall Institute, has passed away due to natural causes." It's not yet clear when she died. "Dr. Goodall’s discoveries as an ethologist revolutionized science, and she was a tireless advocate for the protection and restoration of our natural world," the statement continued. Born in London in 1934, Goodall said her fascination with animals began around when she learned to crawl. In her book, “In the Shadow of Man,” she described an early memory of hiding in a henhouse to see a chicken lay an egg. She was in there so long her mother reported her missing to the police. Goodall began studying chimpanzees in the early 1960s on a research trip to Tanzania. Despite early failed attempts to earn the animals' trust as well as a weekslong bout with what she believed was malaria, she managed to get close enough to make a major breakthrough. By the fall of 1960, she observed a chimpanzee named David Greybeard make a tool from twigs and use it to fish termites from a nest. It was previously believed that only humans made and used tools. “Out there in nature by myself, when you’re alone, you can become part of nature and your humanity doesn’t get in the way,” she told The Associated Press in 2021. “It’s almost like an out-of-body experience when suddenly you hear different sounds and you smell different smells and you’re actually part of this amazing tapestry of life.” Goodall has earned top civilian honors from a number of countries, including Britain, France, Japan, and Tanzania. She was awarded the Presidential Medal of Freedom in 2025 by then-U.S. President Joe Biden and won the prestigious Templeton Prize in 2021. “Her groundbreaking discoveries have changed humanity’s understanding of its role in an interconnected world, and her advocacy has pointed to a greater purpose for our species in caring for life on this planet,” said the citation for the Templeton Prize, which honors individuals whose life’s work embodies a fusion of science and spirituality. Goodall was also named a United Nations Messenger of Peace and published numerous books, including the bestselling autobiography “Reason for Hope.” After watching a film in 1986 depicting disturbing experiments performed on laboratory animals, Goodall launched a career in advocacy. She spoke to audiences around the globe in person, and via her podcast, the "Jane Goodall Hopecast." “If one wants to reach people; If one wants to change attitudes, you have to reach the heart," she said during her first episode. "You can reach the heart by telling stories, not by arguing with people’s intellects.” The Associated Press contributed to this report.