Common Eider

The common eider is a type of sea duck. These huge, seemingly cumbersome ducks inhabit the Arctic and Pacific coasts. In Europe, they can be observed along the Atlantic Coast stretching from Norway to France. With a body size of about 70cm, common eiders are larger than our native mallards. The scientific name somateria mollissima is derived from the duck’s extremely soft, light and warm down. “Soma'' is Greek for “body” while “erion”, also Greek, means “wool” and “mollissima” is Latin for “very soft”. The largest European breeding grounds are found in Iceland where the renowned eider down is sustainably harvested in a traditional manner. The common eiders found on Iceland are well adapted to human presence and breed in large colonies on suitable farmsteads. They colonise literally every spare centimetre here in order to find shelter. During the incubation period, humans defend “their'' colonies against predators, such as arctic foxes. The result is an increase in brood size, as well as an augmented down harvest for their human protectors. After the breeding season is over, the nests, which have been lined with the especially fine down breast feathers, are collected. They are then dried and the dirt, seaweed and other plant parts are removed from the feathers. This process takes a considerable amount of time and effort. Processing one kilogram of down requires the collection of around 60 nests. Eiderdown is especially light and warm. When examined under the microscope, one can make out a chaotic arrangement in the feather structure. The barbule threads wind around each other with their numerous pronged hooklets catching on each other. This leads to the formation of innumerable air chambers. The male and females have very different breeding plumages. The females remain a plain yellow-brownish colour with dark bands throughout the year. The male, on the other hand, has white feathers on its upperparts, breast, throat and head. The male crown is black with a white patch in the middle and on the back of the head it is possible to discern a green sheen among the feathers. The large greenish bill stretches far back into the forehead and is shaped like a wedge. Its underparts are black and its legs are green. Common eiders may either be partial migrators or residents. Large swarms of birds that are neither breeding nor moulting can be seen in the Wadden Sea.