Scientific name: Somateria mollissima
Status: Resident breeder and winter visitor
Breeding birds: 27,000 pairs
Wintering birds: 63,000
Conservation status: Amber
Length: 50 – 71 cm
Wingspan: 80 – 110 cm
Weight: 2 kg
The eider is the UK’s largest duck. Its plumage changes several times as it matures with juveniles having blackish brown feathers.
Adult males are olive-brown and white in winter and black and white with a small patch of emerald green on their heads in the summer.
Female eiders are rust coloured in the summer which provides good camouflage against rocks and vegetation.
Eiders nest in early summer in colonies of up to 10,000. The female builds the nest in the ground using vegetation and down plucked from her breast.
Eiders lay 1-14 eggs that are olive or green coloured. Chicks can leave the nest within 24 hours and fledge in late August.
Eiders dive for food which includes shellfish in particular, mussels, clams, scallops and crabs, sea urchins and starfish. They will also eat insects.
Where to see them
Eiders can be seen all year round in breeding areas. They are found in the north of England, and the west coast of Scotland as well as Northern Ireland.
During winter they are also found on the east coast and south coast as far as Cornwall.
Did you know?
Eiders are known as cuddy ducks after St Cuthbert, the patron saint of Northumberland, who made the eider ducks on The Farnes a protected species.