American Black Duck vs Brazilian Merganser
Anas rubripes compared with Mergus octosetaceus
Side-by-Side Comparison
| Attribute | American Black Duck | Brazilian Merganser |
|---|---|---|
| Scientific Name | Anas rubripes | Mergus octosetaceus |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Critically Endangered |
| Length | — | — |
| Wingspan | 53.4 cm (21.0 in) | 39.2 cm (15.4 in) |
| Weight | 1211.25 g (42.73 oz) | 827.6666666666666 g (29.20 oz) |
| Diet | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Dives for small fish in fast-flowing South American rivers. Critically endangered; uses serrated bill to … |
| Clutch Size | 1-17 | 5-8 |
| Population Trend | — | — |
Habitat Comparison
Shared Habitats
American Black Duck only
Brazilian Merganser only
None
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.
Brazilian Merganser
Male produces a harsh, rasping call; female gives a guttural, grunting series. Critically endangered; quiet vocalizations suit its secretive lifestyle in fast-flowing Brazilian mountain rivers.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Brazilian Merganser
Critically endangered; restricted to a few rivers in southern Brazil, Argentina, and Paraguay. Found on fast-flowing rivers in Atlantic Forest.
Conservation Status
American Black Duck
Brazilian Merganser
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 …
Brazilian Merganser
Male has dark glossy greenish-black head with long shaggy crest; finely vermiculated grey body, white wing patch. Female similar but with rufous-chestnut wash on head and shorter crest.
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.
Brazilian Merganser
One of the world's rarest waterfowl (~830 g), family Anatidae, with a serrated bill and dark green head with bushy crest. Inhabits fast-flowing clear rivers in the Atlantic Forest of Brazil, Argentina, and Paraguay. Feeds on fish and aquatic invertebrates. Critically Endangered; fewer than 250 mature individuals remain due to dam construction and river degradation.