American Black Duck vs Spectacled Eider
Anas rubripes 比較対象 Somateria fischeri
Side-by-Side Comparison
| 属性 | American Black Duck | Spectacled Eider |
|---|---|---|
| 学名 | Anas rubripes | Somateria fischeri |
| 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) | 49.2 cm (19.4 in) |
| 体重 | 1211.25 g (42.73 oz) | 1443.75 g (50.93 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Dives for bivalves, crustaceans, and aquatic insects in shallow Arctic coastal and freshwater habitats. Insects … |
| 一腹卵数 | 1-17 | 1-9 |
| 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.
Spectacled Eider
Male gives a low, melodious aah-ooo cooing; female produces a guttural, grunting call. The male's ghostly, organ-like cooing call carries across Arctic tundra ponds in the breeding season.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Spectacled Eider
Breeds on coastal tundra of western and northern Alaska. Winters along the Bering Sea coast from Alaska to Kamchatka. Largely sedentary.
保全状況
American Black Duck
Spectacled 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 …
Spectacled Eider
Male has white back and black breast with pale sage-green head framed by large white goggle-like spectacles edged black. Female mottled tawny-brown with faint spectacle outline.
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。
Spectacled Eider
A medium-large sea duck of the family Anatidae, weighing ~1.4 kg with distinctive pale green goggles in males. Breeds on Arctic tundra of Alaska and Russia; winters in pack ice of the Bering Sea. Dives for benthic invertebrates and mollusks. Near Threatened due to population declines linked to lead poisoning and habitat change.