Human beings, because we're so clever, have removed every single one of those population limiting factors... So nothing controls our increase in numbers except our own wish. Since I first started making television programs, the population of the world has increased three times. That's an extraordinary notion. Can it increase four times? Can it increase five times? The Earth is a finite size. So a point will eventually come when we run out of food, when we run out of space and when we will have destroyed most of the natural world. So ought we to do something about it before that happens?

What I am interested in with birds, just as I am with spiders or monkeys, is what they do and why they do it.

London has fine museums, the British Library is one of the greatest library institutions in the world... It's got everything you want, really.

I often get letters, quite frequently, from people who say how they like the programmes a lot, but I never give credit to the almighty power that created nature.

You'll find people where their conditions aren't changing in any way, its rather rare for them to be happy.

I'm a humanist. I'm neither one side nor the other.

Birds are the most popular group in the animal kingdom. We feed them and tame them and think we know them. And yet they inhabit a world which is really rather mysterious.