Ravens are the largest birds in the crow family, and have a very large beak. You will probably hear a raven before you see it - they have a very deep call (cronk-cronk). I do not see ravens very often in Northumberland, they seem to be confined to the more remote areas. There are often two were circling the grounds around the house and top lakes. Although their silhouette is quite distinctive, with large 'fingers' on their wings and a broad chisel shaped tail, they can be confused with other large corvids. However, they usually make a lot of noise! and their cronking leaves no doubt as to what they are.