It is not just owls which produce pellets – regurgitated bundles of undigested, undigestible material. Many other birds also regurgitate them, which when analysed reveal a lot of information about a particular bird’s diet. These include birds of prey, herons, gulls, shrikes, crows, kingfishers, grebes and even waders. Pellets from different types of bird are generally distinguished by size, form, consistency and cohesiveness and the material that comprises them. Owls have particularly well defined pellets and their relatively mild digestive systems mean that the regurgitated material, particularly bones remain well intact (see right). Gently teasing apart an owl pellet, using tweezers and with the aid of water, is a brilliant way of finding out what the owl has been eating.