American Black Duck vs Common Eider
Anas rubripes compared with Somateria mollissima
Side-by-Side Comparison
| Attribute | American Black Duck | Common Eider |
|---|---|---|
| Scientific Name | Anas rubripes | Somateria mollissima |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Near Threatened |
| Length | — | — |
| Wingspan | 53.4 cm (21.0 in) | 56.0 cm (22.0 in) |
| Weight | 1211.25 g (42.73 oz) | 2042.8333333333333 g (72.06 oz) |
| Diet | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Dives for blue mussels, clams, and crustaceans in shallow coastal waters. Swallows shellfish whole and … |
| Clutch Size | 1-17 | 2-7 |
| Population Trend | — | — |
Habitat Comparison
American Black Duck
Freshwater and brackish wetlands in eastern North America from Atlantic Canada south along the coast to Georgia. Breeds in northern bogs and wetlands. Winters on coastal marshes, estuaries, and freshwater lakes.
Song & Call Comparison
American Black Duck
Female produces a loud, deep quacking series; male gives a low, raspy grunt. Voice is deeper and huskier than a Mallard; pairs call powerfully across northeastern North American wetlands.
Common Eider
Male produces a loud, resonant ah-WOOO cooing; female gives a deep, guttural quacking series. The male's iconic moaning call echoes across North Atlantic coastlines; a classic seaduck sound.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Common Eider
Breeds on Arctic and subarctic coasts from the North Atlantic to the Pacific. Winters along coasts of northwestern Europe and eastern North America.
Conservation Status
American Black Duck
Common Eider
How to Tell Them Apart
American Black Duck
Sooty dark brown body; head and neck paler buff with dark streaking. Iridescent purple speculum without white border. Males have yellow-green bill; females olive with orange blotches. Silvery underwings in …
Common Eider
Male is strikingly pied: white back, neck, and breast contrasting with black cap, belly, and flanks; nape washed pale lime-green. Female uniformly barred warm tawny-brown with darker streaks.
About These Birds
American Black Duck
A large dark brown dabbling duck closely resembling a very dark female Mallard, with purple speculum, yellowish-olive bill in males, and orange legs. Common in eastern North America. Hybridizes freely with Mallard; pure populations declining in the interior.
Common Eider
The heaviest duck in the Northern Hemisphere (~2 kg), family Anatidae. Breeds colonially on rocky coasts and islands of the North Atlantic and Arctic. Dives for mussels and crustaceans in shallow marine waters. Females line nests with insulating down. Near Threatened due to recent declines in parts of its range from hunting and pollution.