Poll: Are you in favour of zoos?

The veteran naturalist, 90, said that it was "hardly surprising" that the gorilla got "fed up", after being subjected to intrusion by visitors for most of the day.

Visitors to ZSL London Zoo described fearing for their safety as they were ordered to take cover in buildings when the mammal got out of its den last week.

Sir David, 90, said that he felt "deep, deep sympathy and sorrow" for the gorilla.

"They are wonderful animals, gorillas. They are animals which guard their privacy," he said.

"In the forests of west Africa, they don't live out in the open. They aren't stared at by people. They value their privacy."

The wildlife presenter urged visitors to show more compassion towards the animals.

"To be subjected to ... to have a panel of glass, for 10 hours a day or whatever it is...

"If the people were respectful that would be something," he said.

"Sometimes visitors to zoos are not respectful and they start shrieking or waving their arms in order to get the poor gorilla to do something.

"You might think, oh they're just animals. They are not just animals. They are related to us. They value their privacy. Just imagine what it's like to be there..."

Sir David added: "That finally the alpha male, the big gorilla, got fed up with it, is hardly surprising."

He told the ITV programme: "There's a lot has to be said for zoos but they have to bear in mind the sensitivity of animal.

"A gorilla is not like a fish. A gorilla is closely related to us. It has feelings. It can get distressed easily and they do. We have to pay attention to that."

The broadcaster said that the glass panels at the zoo could be replaced with peepholes so that the animals could still enjoy some privacy.

But he admitted that it could be difficult at a hugely popular zoo.

He said: "Maybe the solution is that people should not be allowed to be behind big sheets of glass but look behind peepholes so that the gorillas don't realise (they are being watched) but that's very difficult to do in a zoo where there are tens of thousands of people wanting to see these animals."

Sir David said that while animals were in danger of extinction, zoos still have an important function.

"It would be nice to think that they were safe in the wild but they aren't. And mountain gorillas, 30 years ago, were in very great danger of extinction," he said.

"And it might have been that they could only have survived in zoos. One of the functions of zoos is to preserve species in danger of extinction ... It's a pity they're always in danger of extinction. If we could get rid of that then perhaps there would be no need for zoos.

"It is important for people to be able to see what these wonderful creatures are like and to understand the responsibility that the human race has towards gorillas."