The tufted duck (Aythya fuligula) has an obvious head tuft that gives the species its name. It is a medium-sized diving duck, smaller than a mallard. It is black on the head, neck, breast and back and white on the sides. The adult male is all black except for white flanks and a blue-grey bill. The adult female is brown with paler flanks, and is more easily confused with other diving ducks. The Tufted Duck has increased its range and numbers in the past 100 years – it now breeds across Eurasia from Iceland and the British Isles east across Russia and Siberia. An increased availability of open water due to gravel extraction and man-made lakes offer the ideal feeding habitat for them. This Old World bird is a counterpart of the Ring-necked Duck of North America.