The least I can do is speak out for those who cannot speak for themselves.

Anyone who tries to improve the lives of animals invariably comes in for criticism from those who believe such efforts are misplaced in a world of suffering humanity.

To me, trees are living beings and they have their own sort of personalities.

It was because the chimps are so eye-catching, so like us and teach us so much that my work was recognised worldwide.

There would be very little point in my exhausting myself and other conservationists themselves in trying to protect animals and habitats if we weren't at the same time raising young people to be better stewards.

Lasting change is a series of compromises. And compromise is all right, as long your values don't change.

Just think of the trust that often exists in soldiers. Within their own unit, you could say they have to trust each other. A spirit of camaraderie builds up and, in the end, they will risk their lives for each other. They may even go so far as to dehumanise the other, enemy group - a mechanism you can also observe in chimps.