American Black Duck vs Steller's Eider
Anas rubripes مقارنةً بـ Polysticta stelleri
Side-by-Side Comparison
| السمة | American Black Duck | Steller's Eider |
|---|---|---|
| الاسم العلمي | Anas rubripes | Polysticta stelleri |
| الرتبة | Anseriformes | Anseriformes |
| الفصيلة | Anatidae | Anatidae |
| حالة الحفاظ | Least Concern | Vulnerable |
| الطول | — | — |
| طول الجناح | 53,4 cm (21.0 in) | 40,7 cm (16.0 in) |
| الوزن | 1211,25 g (42.73 oz) | 815,75 g (28.77 oz) |
| النظام الغذائي | -- | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal and estuarine habitats; diet invertebrate-dominated. |
| عدد البيض في الوضع | 1-17 | 3-10 |
| 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.
Steller's Eider
Breeds on low-lying coastal tundra in Arctic Russia and occasionally Alaska. Winters on shallow rocky sea coasts, kelp beds, and sheltered bays in the Baltic Sea and Pacific coast of Alaska. Listed as Vulnerable.
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.
Steller's Eider
Male produces a low, soft cooing note; female gives a guttural, grunting purr. Quieter than other eiders; the male's gentle cooing is unlike the louder calls of the Common Eider.
Geographic Range & Migration
American Black Duck
Steller's Eider
Breeds in boreal Canada and Alaska; winters along Pacific and Atlantic coasts and on large interior lakes of the US.
حالة الحفاظ
American Black Duck
Steller's 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 …
Steller's Eider
Males have white head with green nape spot, black eye patch and chin; orange-buff underparts; black back with white wing patches. Females mottled dark brown with blue speculum bordered white. …
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.
Steller's Eider
A small sea duck. Males have a white head with green facial markings, black throat patch, chestnut underparts, and white back; females are dark brown. The smallest eider. Breeds in Arctic tundra; winters in Baltic Sea and Alaskan coastal waters. Vulnerable to contaminants and oil spills.