The Beak, Bill, or rostrum is an external anatomical structure of birds. The most important function of the bird bill is feeding and for grooming. Other functions are manipulating objects, fighting, killing prey, feeding young, probing for food and courtship. The bill is one of the characteristics used to identify the birds. By looking at the bill of the bird you can learn about their behaviour and thinking about what it eats. Although beaks vary in size, shape and colour but still they share a similar underlying structure. There is a list of birds which have beautiful red beaks.