American Black Duck vs Ruddy Duck
Anas rubripes 比較対象 Oxyura jamaicensis
Side-by-Side Comparison
| 属性 | American Black Duck | Ruddy Duck |
|---|---|---|
| 学名 | Anas rubripes | Oxyura jamaicensis |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 53.4 cm (21.0 in) | 27.9 cm (11.0 in) |
| 体重 | 1211.25 g (42.73 oz) | 586.6666666666666 g (20.69 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Dives for aquatic plant seeds, roots, and invertebrates in freshwater marshes. Uses stiff tail as … |
| 一腹卵数 | 1-17 | 5-15 |
| 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.
Ruddy Duck
Male produces a mechanical, drumming bok-bok-bok staccato beat; female gives a harsh, nasal quack. The male's rapid drum-roll call on the bill during display is startlingly loud and distinctive.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Ruddy Duck
Breeds across interior North America from western Canada south to Mexico. Winters on coasts and inland waters south to northern South America.
保全状況
American Black Duck
Ruddy Duck
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 …
Ruddy Duck
Breeding male has vivid rufous-chestnut body, black crown, white cheeks, and bright sky-blue bill; stiff tail often cocked upright. Female is dull brown with pale cheek crossed by single dark …
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。
Ruddy Duck
北米で繁殖し、中米・南米北部で越冬する小型の潜水ガモ（体長35〜43cm）。雄の繁殖羽は栗色の体に白い頬、青い嘴が特徴的。Oxyura jamaicensis（ルディダック）は特徴的な扇状の尾羽を立てる姿勢で知られる。北米原産だがヨーロッパに移入・定着し、近縁のフェルギネオウ・ホワイトヘッドダックとの交雑が問題となっている。Anatidae科。