diver

Any of four species of marine bird of the order Gaviiformes, specialized for swimming and diving, found in northern regions of the northern hemisphere. The legs are set so far back that walking is almost impossible, but they are powerful swimmers and good flyers, and only come ashore to nest. They have straight bills, short tail-feathers, webbed feet, and long bodies; they feed on fish, crustaceans, and some water plants. During the breeding period they live inland and the female lays two eggs which hatch into down-covered chicks. Of the four species, the largest is the white-billed diver Gavia adamsii, an Arctic species 75 cm/2.5 ft long.