Common eider — Ducks Unlimited Canada
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Know your waterfowl

Common eider

Somateria mollissima

Common eider drake. ©DUC

The common eider, a sea duck, is the largest duck in the northern hemisphere.


  • Distinctive long wedge-shaped bill
  • Males average over 2 kg
  • Breeding male has white face, neck, breast and back, with black crown, sides, belly and tail; nape is green (males do not attain breeding plumage until three years of age); bill is grey-green, yellow or orange
  • Female is brown with black barring, especially along the sides; bill is grey


  • Female alone incubates eggs for 26 days after she lays the 2nd or 3rd egg
  • Female does not eat during the incubation period and takes short breaks only to drink – hens can loose up to 45% of their body mass during this period
  • Non-breeding females often join breeding females to help protect the young from predators

Habitat: Breeds on coastal islands or along ponds and lagoons near the ocean. Winters offshore near marine shoals.

Range: Breeds on marine coasts from Alaska and arctic islands to Hudson Bay and James Bay and along the east coast as far south as Maine. Winters in southern Alaska, Hudson Bay, and the northern Atlantic southward to New Jersey.

Diet: About 75 per cent of their diet is mollusks, the rest being a variety of crustaceans. Dive to depths of 20 m to feed on mollusks and crustaceans including mussels, clams, scallops and urchins.

Interesting Facts

  • Largest duck in North America
  • The common eider is the most numerous eider
  • Eider down is one of the lightest and most effective insulators known.

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