By their white head they are unmistakable with other ducks. The male has a larg blue bill and long stiff tail and white head with black crown and females have dark brown head and dark striped cheek patern. Length is 43-48 cm and weight is 580-750 g.
These birds dive and swim under water, they live in reedy. Shallow lakes, and brackish lagoons. They from large flocks in winter and feed together on insect, larva and submerged plant material and seeds. Dive continuously and staying under water for around forty seconds at a time and in flight they look elongated with short uniform wings appearing far forward on body. In late winter they moult and are rendered flight.
The drastic decline in population of white headed ducks have recently intensified in Iran as a result of habitat loss and hunting .
The white-headed duck probably had a global population of over 100000 in the early 20th century; in the 1930s an estimated 50,000 wintered on the Caspain sea. However, by 1991vthe population was estimated at a mere 19000 ducks. This reduction in numbers was matches by a large decline in breeding range.