Jane Goodall, renowned chimpanzee researcher and animal advocate, dies at 91

Dr. Jane Goodall, who will be remembered as an advocate for animals and a renowned chimpanzee researcher, died due to natural causes, the Jane Goodall Institute announced in a Wednesday statement.

She was 91.

"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 announcing her death said.

Goodall was in California at the time of her death, on a speaking tour in the U.S., the statement said.

Goodall was made famous for her work with chimpanzees. Goodall began studying the animals in Tanzania in the 1960s, and she published some of the first observations of chimpanzees' use of tools, communication, and their complex social structures in scientific journals.

Her work paved the way for decades of field research on the behavior of primates in natural settings.

"A long and fine life led," said Ingrid Newkirk, founder of People for the Ethical Treatment of Animals or PETA. Goodall "helped PETA end the confinement of chimpanzees locked in barren, solid metal chambers for experiments, calling what we exposed and her visit to see them as 'the worst day of my life.'"

According to the Jane Goodall Institute, which she founded in 1977, she "went into the forest to study the remarkable lives of chimpanzees—and she came out of the forest to save them."

According to the foundation's website, when Goodall realized chimps' survival was threatened by habitat destruction and illegal trafficking, she "developed a breakthrough approach to species conservation that improves the lives of people, animals and the environment by honoring their connectedness to each other."

Goodall was 26 when she visited Tanzania for the first time to explore the world of wild chimpanzees. She took an "unorthodox approach" to her research, the foundation said, "immersing herself in their habitat and their lives to experience their complex society as a neighbor rather than a distant observer."

Goodall sat down with "Call Her Daddy" host Alex Cooper for a nearly hour-long interview on her life and her work earlier this year.

She remarked to Cooper that she was lucky she didn't have to fight for a place in a male-dominated field when she began her work because there was hardly a field in existence at all at the time. That first expedition to Tanzania to study primates was on a shoestring budget funded by a philanthropist, and the British government would only support it if she had someone with her.

Her mother, who always supported her dreams, volunteered to go with her, Goodall said.

"Everyone said, 'That’s ridiculous. I mean you don’t have any money, Africa’s far away and you’re just a girl,'" Goodall told Cooper. "Not my mum. She said if you really want to do something like this, you’re going to have to work really hard, take advantage of every opportunity, and if you don’t give up, hopefully you’ll find a way."

It’s a message she said she shared with the world.

Goodall had only six months of funding, and the first four months were fruitless as the primates were too skittish to allow her close enough to observe. But one finally adjusted to her presence long enough for her to make the breakthrough discovery that chimpanzees create and use tools in the wild.

“The reason why this was so exciting was because, at that time, it was thought by Western science that only humans used and made tools. We were defined as man, the toolmaker,” Goodall recalled. “And so when I wrote to my mentor, Louis Leakey, he was just so excited.”

That discovery piqued the interest — and funding — of National Geographic and ultimately changed the course of Goodall’s career.

This article was originally published on NBCNews.com