A diving duck with a grey body, black breast and tail, and males show a chocolate- brown head, with an intense red iris. The female, as with almost all ducks, is duller in plumage. They prefer water bodies with abundant bank-side vegetation, feeding on invertebrates captured whilst diving. In Extremadura they only breed in the La Albuera lakes, the Llanos de Cáceres and the Vegas Altas of the Guadiana river. They are much more widespread in winter.