American Black Duck vs Crested Shelduck
Anas rubripes so với Tadorna cristata
Side-by-Side Comparison
| Thuộc Tính | American Black Duck | Crested Shelduck |
|---|---|---|
| Tên Khoa Học | Anas rubripes | Tadorna cristata |
| Bộ | Anseriformes | Anseriformes |
| Họ | Anatidae | Anatidae |
| Tình Trạng Bảo Tồn | Least Concern | Critically Endangered |
| Chiều Dài | — | — |
| Chiều Dài Sải Cánh | 53,4 cm (21.0 in) | 59,8 cm (23.5 in) |
| Khối Lượng | 1211,25 g (42.73 oz) | 1235,0 g (43.56 oz) |
| Chế Độ Ăn | 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; … |
| Số Trứng | 1-17 | 10 |
| Population Trend | — | — |
Habitat Comparison
Môi Trường Sống Chung
American Black Duck only
Crested Shelduck only
Không
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.
Tình Trạng Bảo Tồn
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
A mysterious possibly extinct shelduck known from only a handful of specimens collected in Korea and Siberia before 1916. Males had a black head with green sheen, white crest, and colorful body. No confirmed sightings since 1971. Possibly on the edge of extinction or already extinct.