Prince William is paying tribute to Jane Goodall after her death at the age of 91.

On Thursday, Oct. 2, the Prince of Wales shared a rare personal message via Instagram Stories about the conservationist’s passing.

“The world has lost an extraordinary voice with the passing of Dame Jane Goodall,” his message began. “Her boundless curiosity, compassion, and pioneering spirit transformed our understanding of the natural world.”

He continued, “She challenged us all to make a difference and inspired me and countless others to work to protect our planet.”

“Jane Goodall made a difference,” he concluded the message, which was signed off with his initial, “W” to indicate it was a personal tribute from the 43-year-old royal.

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The Prince of Wales’ tribute follows his brother, Prince Harry, 41, and sister-in-law, Meghan Markle, 44, sharing their own moving words.

“Dr. Jane Goodall DBE was a visionary humanitarian, scientist, friend to the planet, and friend to us,” the couple said in a statement obtained by PEOPLE.

“Her commitment to changing lives extends beyond what the world saw, and also to what we personally felt,” they continued, adding of their own personal connection to Goodall.

“She held our son, Archie, when he was first born, and showered love and care to those who were privileged to know her. She will be deeply missed.”

The renowned conservationist and animal welfare advocate died in Los Angeles of natural causes while on a speaking tour, the Jane Goodall Institute announced on Wednesday, Oct. 1. She was 91.

She is survived by her son, Hugo, and three grandchildren.

“Dr. Goodall’s discoveries as an ethologist revolutionized science, and she was a tireless advocate for the protection and restoration of our natural world,” her institute said.

Other famous faces who have shared their own tributes to Goodall include actor and environmental activist Leonardo DiCaprio, who called her a “true hero for the planet, an inspiration to millions, and a dear friend.”

Jane Fonda said that her “heart breaks at the news” of Goodall’s passing, while Michael Douglas shared, “RIP to my fellow UN Messenger of Peace, Dr. Jane Goodall. Her legacy will forever be remembered for her unwavering dedication to our planet.”

Al Roker remembered her as a “gentle soul but a fierce champion,” while  Julia Louis-Dreyfus said she was “so blessed and so grateful to have crossed paths with this wise giant.”