"Jumping on animals. I regret that," he states. I blink in disbelief. It is as if Judi Dench had admitted to glue-sniffing. Attenborough explains. "Fifty years ago, I used to go along, chase a giant anteater and pull it by the tail so we could film it. I am sorry about that sort of thing. But those were different days."

Then there was the time he and his crew were stuck in Borneo and strapped for something to film. "I found a little crocodile and we did a cod sequence with it. We filmed it close up so that it looked like a really big crocodile. I then took off my shirt and jumped on it. Everyone thought I had a fight with a full-sized crocodile. 'God you were brave,' they told me. I wish I hadn't done that."

And as for eating turtle eggs, he pulls a face. "They were horrible, salty. I wished I hadn't done that either."

As crimes against nature, these are minor transactions, it must be admitted. Yet they are informative – for it is easy to forget how attitudes to wildlife have changed since Attenborough began his career in 1952 on programmes such as The Pattern of Animals and, later, Zoo Quest. Wild creatures were still viewed from a Victorian perspective in those days. They were there to be tracked, captured, tied up and brought back to Britain to be goggled at. Attenborough was no different from other naturalists at the time, he admits.

Zoo Quest was certainly made in that mould, he believes. For the nine years it aired, Attenborough would travel with staff from London Zoo to a tropical country to capture an animal for the zoo's collection, a practice that was considered to be perfectly acceptable at the time. Attenborough's first assignment was to track down a white-necked Picathartes in Sierra Leone on the grounds that no other zoo in Europe had one or even knew what it looked like. "I thought: 'Oooh, a bird that no one has ever even seen. I must become the first European to get one.' It was very childish really."