American Black Duck vs Common Eider
Anas rubripes 比較対象 Somateria mollissima
Side-by-Side Comparison
| 属性 | American Black Duck | Common Eider |
|---|---|---|
| 学名 | Anas rubripes | Somateria mollissima |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Near Threatened |
| 体長 | — | — |
| 翼開長 | 53.4 cm (21.0 in) | 56.0 cm (22.0 in) |
| 体重 | 1211.25 g (42.73 oz) | 2042.8333333333333 g (72.06 oz) |
| 食性 | 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 … |
| 一腹卵数 | 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.
保全状況
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
北米東部の湿地、沼、河川に生息するカモ（体長53〜61cm）。全体的に暗褐色でマガモの雌に似るが、嘴の色や翼鏡の色が異なる。Anas rubripes（アメリカクロガモ）は海岸の塩性湿地から内陸の淡水域まで幅広く利用し、マガモとの雑種が多く観察される。Anatidae科。
Common Eider
北極圏から温帯の海岸で繁殖する大型の潜水ガモ（体長50〜71cm）。雄は白・黒の体に緑の後頭部が特徴的。Somateria mollissima（ホンケワタガモ）の雌は抱卵時に自分の胸の羽（エイダーダウン）を抜いて卵を覆い、これが世界最高の天然断熱材として知られる。Anatidae科。