The common eider, also called St. Cuthbert's duck or Cuddy's duck, is a large sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters further south in temperate zones, when it can form large flocks on coastal waters. It can fly at speeds of up to 70mph!
The common eider is both the largest of the four eider species and the largest duck found in Europe.
The male is unmistakable, with its black and white plumage and green nape. The female is a brown bird, but can still be readily distinguished from all ducks, except other eider species, on the basis of size and head shape.
This species dives for crustaceans and molluscs, with mussels being a favoured food. The eider will eat mussels by swallowing them whole; the shells are then crushed in their gizzard and excreted.