Sir David Attenborough is a 'national treasure' says Duke of Cambridge

Sir David Attenborough has been called a "national treasure" by the Duke of Cambridge, who added that it is fitting that the broadcaster and the Queen are celebrating their 90th birthdays just weeks apart.

Prince William paid tribute to Sir David on a special programme to mark the broadcaster's milestone birthday on May 8 called 'Attenborough At 90'.

William said the naturalist was "the single most important impact in my conservation thinking".

Several others also paid tribute to Sir David in the television special hosted by Kirsty Young, including Prime Minister David Cameron and astronaut Tim Peake.

Mr Cameron wished Sir David a happy birthday on behalf of the country, and said he had grown up watching and learning from the broadcaster.

Peake, speaking in a message recorded on the International Space Station, wished Sir David a happy birthday and said: "Your adventures and your words have inspired us enormously and changed the way that we look at our earth."

The hour-long programme celebrates Sir David's contribution to our understanding of the natural world and to the development of television broadcasting.

Sir David also talks about some of his incredible animal adventures, such as his interaction with a blind baby hippo and his legendary gorilla encounter in 1979's Life On Earth.

Sir David explained how the groundbreaking scenes came about accidentally, as he had merely planned to get close to the animals to narrate a piece about the use of the opposable thumb.

Asked what inspires him to continue, Sir David said making programmes, particularly with people he loves to work with, is just "huge fun".

"I feel constantly embarrassed about the amount of credit I get for the amount of work that many many other people are actually in fact doing," he said.

"I've had a singularly, unbelievably fortunate time."