The common eider is both the largest of the four eider species and the largest duck found in Europe and in North America. It measures in length, weighs and spans across the wings. It has a bulky shape and large, wedge-shaped bill. The male is unmistakable, with its black and white plumage and green nape. The female is a brown bird. It can be told apart from all ducks, except other eider species, because of size and head shape. This duck's call is a pleasant "ah-ooo". The species is often readily approachable.