This mid-sized diving duck is easily recognizable by the male’s distinctive appearance: a dark rusty head, a pale gray body with a black breast, and a broad pale bluish band on the bill. The female is more nondescript, appearing gray-brown overall with subtle pale head markings. Both sexes have a sloping forehead and a dark gray bill with a pale band near the tip. In flight, they appear grayish overall and lack the bold white wing stripe seen in some other species. They inhabit marshy and reed-fringed lakes as well as open reservoirs, and can be found locally on the sea during winter, especially when lakes freeze. In winter, they are often seen in flocks and may associate with Tufted Ducks. Their diet mainly consists of diving for food.