Ravens used to be a rare sight in the East of England, and also in some areas of eastern Scotland. But, like buzzards, these great black birds are spreading out from the mountains and moors of the West. This year some have even been sighted north of London. Now, as the summer’s families break up, some of the young birds are likely to be heading eastwards. These may spearhead further extensions of their breeding range. The old birds usually stay close to the cliffs where they have nested, and often use the same nest year after year. They are half as large again as crows, though size can be hard to judge when these birds are high in the sky. Their large, powerful beak and their wedge-shaped tail help to distinguish them. Above all, they have a deep, rumbling croak that can make you think the earth is shaking, and that makes the cawing of rooks and crows seem very feeble yelping by comparison.