David Attenborough is standing in a quarry in Anglesey, watching a large black bird fly overhead and land on a rock ledge.

"The raven is a remarkable bird. It is the largest of the crow family, bigger than a buzzard. In the UK, they are found in mountains and moorlands, where they nest on rocky outcrops like this one. They usually eat carrion but they would be capable of killing small mammals and birds – so farmers worry about them taking sick lambs. Because of their size, their black plumage and hoarse cry they are often regarded as birds of evil omen. This seems rather unfair on the raven."

The camera zooms in to show the raven on its nest, tearing up a dead rabbit and feeding it to an ungainly chick.

"Like all the crow family, the raven is a very intelligent bird. They can easily learn to mimic a range of sounds including human speech. There are all sorts of stories about ravens warning humans of danger.

The oddest one concerns a man who was working in his study when he heard a tapping sound. He opened the door and found nothing. However, the tapping continued until he realised that the noise was coming from the window. When he opened the window, a raven flew in and landed on a bust of Pallas above the door. The man tried talking to the raven, who kept repeating the word ‘Nevermore’. The man, who was grieving over the death of his beloved, grew seriously alarmed. He was convinced the raven was saying he would never be reunited with the lady in heaven. In the end, he became so depressed he was admitted to a lunatic asylum. No-one knows what happened to the raven.

Although the story sounds far-fetched, there is a possible explanation. A wild raven would be most unlikely to fly into a room, so this must have been a tame bird. Probably, the previous owner taught it to say the word ‘Nevermore’ to obtain food. Perhaps he had a ghoulish sense of humour and wanted to scare his friends!

Although ravens declined, and retreated to the mountains of the north and west, they are beginning to extend their range. I certainly would want to see this magnificent bird taking its proper place in the British countryside."