African Black Duck vs Steller's Eider
Anas sparsa 比較対象 Polysticta stelleri
Side-by-Side Comparison
| 属性 | African Black Duck | Steller's Eider |
|---|---|---|
| 学名 | Anas sparsa | Polysticta stelleri |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Vulnerable |
| 体長 | — | — |
| 翼開長 | 49.5 cm (19.5 in) | 40.7 cm (16.0 in) |
| 体重 | 996.8333333333334 g (35.16 oz) | 815.75 g (28.77 oz) |
| 食性 | Eats molluscs, crustaceans, and aquatic invertebrates; dives in coastal and freshwater habitats; diet heavier in … | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal and estuarine habitats; diet invertebrate-dominated. |
| 一腹卵数 | 4-9 | 3-10 |
| Population Trend | — | — |
Habitat Comparison
African Black Duck
Fast-flowing rocky rivers and streams, mountain gorges, and waterfalls from sea level to 4,000 m across sub-Saharan Africa from Ethiopia and Kenya south to the Cape. Requires clear turbulent water with boulders.
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
African Black Duck
Produces a harsh, resonant quacking call; alarm is a loud, emphatic quack repeated rapidly. Both sexes call with strong quacking; pairs duet with synchronized calls along African rivers.
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
African Black Duck
Resident across South and Southeast Asia, from India to southern China and the Philippines. Non-migratory in most of its range.
Steller's Eider
Breeds in boreal Canada and Alaska; winters along Pacific and Atlantic coasts and on large interior lakes of the US.
保全状況
African Black Duck
Steller's Eider
How to Tell Them Apart
African Black Duck
Dark blackish-brown plumage with bold white spots on back and scapulars. Iridescent blue-green speculum with white borders. Head dark with pale spots. Bill and legs dark gray. Sexes similar. Fast-flowing …
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
African Black Duck
アフリカンブラックダックはサハラ以南のアフリカの急流河川に生息する特殊なカモです。暗褐色の羽毛と白い斑点が特徴で、水流の速い清澄な渓流を好みます。繁殖期には縄張り意識が強く、ペアで生活します。急流の水生昆虫や甲殻類を主食とします。
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.