The eider is the UK’s heaviest duck and its fastest flying. It is a true seaduck, rarely found away from coasts where its dependence on coastal molluscs for food has brought it into conflict with mussel farmers. Eiders are highly gregarious and usually stay close inshore, riding the swell in a sandy bay or strung out in long lines out beyond the breaking waves. It is an Amber List species because of its winter concentrations.
What they eat:
Shellfish, especially mussels.
This bird species has different identifying features depending on sex/age/season.