Prince William has paid tribute to Dame Jane Goodall and her "pioneering spirit"

William wrote: "The world has lost an extraordinary voice with the passing of Dame Jane Goodall.

"Her boundless curiosity, compassion, and pioneering spirit transformed our understanding of the natural world.

"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."

The message was signed off with the letter W, indicating a personal message from the prince.

William's message came shortly after his estranged brother, Prince Harry and his wife Meghan, Duchess of Sussex paid tribute to their "friend".

A statement from Harry and Meghan - who have Prince Archie, six, and four-year-old Princess Lilibet together - shared with People magazine read: "Dr. Jane Goodall DBE was a visionary humanitarian, scientist, friend to the planet, and friend to us.

"Her commitment to changing lives extends beyond what the world saw, and also to what we personally felt.

"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."

A host of stars have also paid tribute to the animal welfare advocate, including Leonardo DiCaprio, with the One Battle After Another actor urging people to donate to conservation charities in honour of the zoologist.

He wrote on Instagram: "Today we have lost a true hero for the planet, an inspiration to millions, and a dear friend.

"For decades, Jane traveled the world with tireless energy, awakening generations to the wonder of the natural world. She spoke directly to the next generation, instilling hope, responsibility, and the belief that every individual can make a difference. She inspired millions to care, to act, and to hope. She never stopped.

"My deepest condolences to her family. Please join me in honoring her legacy by supporting @janegoodallinst and other conservation groups which she cared about.

"My last message to Jane was simple: 'You are my hero.' Now, we all must carry the torch for her in protecting our one shared home."

Jane Fonda dec lared her "heart breaks at the news" as she celebrated the work of the activist, who was regarded as the world's leading expert on chimpanzees and was known for her 65-year study on the creatures in Tanzania.

She wrote on her own Instagram account: "My heart breaks at the news that the brave, heartful, history-making Jane Goodall has passed. Through her work with chimps, she did more than any human being has, to let us understand the richness of animal lives: their intelligence, skills, unique personalities, use of tools, empathy, suffering when one of theirs was killed.

"I loved her very much. I think the best way we can honor her life is to treat the earth and all its beings like our family, with love and respect. [heart emoji] (sic)"