The common eider is the largest duck in the northern hemisphere; an adult weighs 1300–2660 grams (2.8–5.9 lbs) and is 50–71 cm (20–28 in.) long. Males are somewhat larger than females; size varies among races. The eider is a heavy-bodied sea duck with a relatively short, stout neck and a distinctive long, triangular (wedge-shaped) bill.
Species Knowledge Summary and Information Needs
Pacific Common Eider [PDF]
Northern Common Eider (document coming soon)
Hudson Bay Common Eider (document coming soon)
American Common Eider [PDF]