American Black Duck vs Common Shelduck
Anas rubripes مقارنةً بـ Tadorna tadorna
Side-by-Side Comparison
| السمة | American Black Duck | Common Shelduck |
|---|---|---|
| الاسم العلمي | Anas rubripes | Tadorna tadorna |
| الرتبة | Anseriformes | Anseriformes |
| الفصيلة | Anatidae | Anatidae |
| حالة الحفاظ | Least Concern | Least Concern |
| الطول | — | — |
| طول الجناح | 53,4 cm (21.0 in) | 62,8 cm (24.7 in) |
| الوزن | 1211,25 g (42.73 oz) | 1035,5 g (36.53 oz) |
| النظام الغذائي | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Eats seeds, leaves, and aquatic invertebrates; dabbles in shallow water; diet broadly omnivorous and varies … |
| عدد البيض في الوضع | 1-17 | 3-18 |
| 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.
Common Shelduck
Coastal estuaries, mudflats, saltmarshes, sand dunes, and inland saline lakes from northwest Europe east across Eurasia to China. Winters mainly on tidal estuaries and coastal wetlands. Nests in burrows.
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.
Common Shelduck
Male gives a whistled 'wheee'; female gives a cackling series of rapid nasal 'ak-ak-ak' notes. One of the most sexually dimorphic calls of any shelduck species.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Common Shelduck
Breeds in Siberian tundra; winters in eastern and southern Africa, and in South and Southeast Asia. Trans-hemispheric migrant.
حالة الحفاظ
American Black Duck
Common 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 …
Common Shelduck
White body with dark green head, broad chestnut breastband, and black scapular stripes. Red bill with basal knob in males. Green speculum and black wingtips. Underparts white with black belly …
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.
Common Shelduck
A large distinctive shelduck with a white body, dark green head, broad chestnut breast band, and a bright red bill with a knob in males. Common along European and Asian coasts and estuaries. Nests in rabbit burrows or hollow trees. Large moult migrations concentrate in Germany's Wadden Sea.