Birthday tributes for David Attenborough as he turns 99

David Attenborough feeds a carrot to a wallaby
David Attenborough has dedicated his life to documenting the wonders of the natural world. -AP

A host of celebrities have paid tribute to David Attenborough ahead of his 99th birthday.

The broadcaster and natural historian will turn 99 on Thursday and to mark the occasion, a number of stars were asked about his influence on them.

Actor Morgan Freeman told The Guardian he'd spent "hours captivated by his storytelling and being reminded of the beauty and fragility of the world we share".

"David Attenborough is one of my favourite narrators, bringing the wonders of our planet to life in a way that's both inspiring and unforgettable."

Singer Billie Eilish said David Attenborough's "deep love and knowledge of our planet and the animal kingdom brings out the childlike curiosity within us all. He's a living treasure".

Monty Python star Michael Palin shared some of his memorable encounters with Attenborough.

"When 'Monty Python' first aired, the BBC put it on late, hoping no one would notice," he said.

"At a BBC event, the only one who'd talk to us was David Attenborough, then director of programs, who told us 'the more they tried to stop it being seen, the greater would be our cult following'.

"He was right."

Actress and activist Jane Fonda, praised Attenborough for inspiring people to see the importance of preserving nature.

"I have watched every one of his documentaries. There is so much to learn and love, but particularly how he shows us the interconnectedness of the natural world: everything matters, and we must fight to save it all."

Actress Kate Winslet said Attenborough "remains, for me, an integral part of how things used to be".

"Our more plentiful oceans, our verdant, bulging rainforests, full of species that thrived before their natural habitats came under such serious threat," she said.

"He is someone I would swim through stormy seas to meet. In a declining world when we desperately need compassionate anchors, David is that anchor for so many, showing us depths and beauty that won't be with us forever, forming a picture for future generations of just how vital it is to stay educated, to stay curious."