American Black Duck vs Eastern Spot-billed Duck
Anas rubripes 比較対象 Anas zonorhyncha
Side-by-Side Comparison
| 属性 | American Black Duck | Eastern Spot-billed Duck |
|---|---|---|
| 学名 | Anas rubripes | Anas zonorhyncha |
| 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) | 53.6 cm (21.1 in) |
| 体重 | 1211.25 g (42.73 oz) | 1017.5 g (35.89 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Eats fish, aquatic invertebrates, and amphibians; dives in freshwater rivers; serrated bill grips prey; fish … |
| 一腹卵数 | 1-17 | 7-9 |
| 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.
Eastern Spot-billed Duck
Freshwater lakes, rivers, marshes, and rice paddies in northeastern Asia from eastern Russia and Siberia through China, Korea, and Japan. Winters in southern China and southern Japan.
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.
Eastern Spot-billed Duck
Female produces a loud, descending quacking series; male gives a low, nasal grunt. Vocalizations closely resemble the Indian Spot-billed Duck; pairs call antiphonally on East Asian wetlands.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Eastern Spot-billed Duck
Found in wetlands across Southeast Asia, from India to China, Vietnam, and Indonesia. Largely resident; local seasonal movements.
保全状況
American Black Duck
Eastern Spot-billed 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 …
Eastern Spot-billed Duck
Brown body with pale buff face and throat; dark crown and eye stripe. Yellow-tipped black bill lacking the red spot of Indian Spot-billed Duck. Iridescent green speculum with white border. …
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。
Eastern Spot-billed Duck
オナガガモに似たこのカモは東アジアに分布し、中国、ロシア極東、日本などに生息します。嘴に黄色い斑点があるのが特徴で、湿地や水田、池に生息します。冬季には暖かい地方に渡りますが、一部は通年同じ地域に留まります。