American Black Duck vs Crested Shelduck
Anas rubripes 对比 Tadorna cristata
Side-by-Side Comparison
| 属性 | American Black Duck | Crested Shelduck |
|---|---|---|
| 学名 | Anas rubripes | Tadorna cristata |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保护状况 | Least Concern | Critically Endangered |
| 体长 | — | — |
| 翼展 | 53.4 cm (21.0 in) | 59.8 cm (23.5 in) |
| 体重 | 1211.25 g (42.73 oz) | 1235.0 g (43.56 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Possibly extinct; Crested Shelduck fed on seeds, aquatic plants, and invertebrates near East Asian wetlands; … |
| 产卵数 | 1-17 | 10 |
| 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.
Crested Shelduck
Historically known from coastal Korea, Siberia, and possibly Japan. Habitat preferences poorly known; specimens were collected near coasts and rivers. Possibly extinct.
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.
Crested Shelduck
Critically endangered; last confirmed sightings in 1971. No vocalizations reliably recorded. Presumed similar to related shelducks based on phylogeny but effectively unknown.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Crested Shelduck
Breeds across the Palearctic; winters from West Africa to South Africa. Uses the western and central Palearctic–African flyways.
保护状况
American Black Duck
Crested Shelduck
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 …
Crested Shelduck
Critically rare; known from few specimens. Males dark green head with bushy crest; black and white body with chestnut flanks. Females have white facial markings and brown-barred body. Possibly extinct; …
About These Birds
American Black Duck
A large dark brown dabbling duck closely resembling a very dark female Mallard, with purple speculum, yellowish-olive bill in males, and orange legs. Common in eastern North America. Hybridizes freely with Mallard; pure populations declining in the interior.
Crested Shelduck
冠麻鸭是已知的最后一个可靠标本记录于20世纪初的朝鲜半岛，此后再无确认记录，可能已灭绝。外形与赤麻鸭相似，但雄鸟头顶具绿色羽冠。曾繁殖于朝鲜半岛和中国北部，越冬于中国南部。灭绝原因可能与栖息地丧失和过度猎捕有关，目前仍被列为极危物种（可能已灭绝）。