I suffer much less than many of my colleagues. I am perfectly able to go to Australia and film within three hours of arrival.

Nothing in the natural world makes sense - except when seen in the light of evolution

I can mention many moments that were unforgettable and revelatory. But the most single revelatory three minutes was the first time I put on scuba gear and dived on a coral reef. It's just the unbelievable fact that you can move in three dimensions.

I've been bitten by a python. Not a very big one. I was being silly, saying: 'Oh, it's not poisonous' Then, wallop! But you have fear around animals.

I have no doubt that the fundamental problem the planet faces is the enormous increase in the human population

All our environmental problems become easier to solve with fewer people and harder - and ultimately impossible to solve - with ever more people.

If we and the rest of the back-boned animals were to disappear overnight, the rest of the world would get on pretty well. But if the invertebrates were to disappear, the world's ecosystems would collapse