Black-headed Duck vs White-headed Steamerduck
Heteronetta atricapilla compared with Tachyeres leucocephalus
Side-by-Side Comparison
| Attribute | Black-headed Duck | White-headed Steamerduck |
|---|---|---|
| Scientific Name | Heteronetta atricapilla | Tachyeres leucocephalus |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Vulnerable |
| Length | — | — |
| Wingspan | 34.7 cm (13.7 in) | 55.0 cm (21.7 in) |
| Weight | 528.5 g (18.64 oz) | 3250.0 g (114.64 oz) |
| Diet | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Dabbles for aquatic invertebrates, seeds, and plant material in shallow water; diet shifts more toward … |
| Clutch Size | 2 | 3-6 |
| Population Trend | — | — |
Habitat Comparison
Shared Habitats
None
Black-headed Duck only
White-headed Steamerduck only
White-headed Steamerduck
Rocky coastal shores, sea channels, and sheltered bays along the Patagonian coast of Chubut Province, Argentina. Flightless; strictly coastal. Nests on rocky headlands. Very limited geographic range.
Song & Call Comparison
Black-headed Duck
Male gives a soft, raspy peeping note; female produces a muted quack. An obligate brood parasite with reduced vocalizations; subdued calls suit its secretive lifestyle among Argentine reeds.
White-headed Steamerduck
A deep, rattling call from Patagonian coastal habitat. VU status; calls similar to Magellanic Steamerduck but possibly subtly distinct. Vocalizations in wild remain understudied.
Geographic Range & Migration
Black-headed Duck
Resident in southern South America from southern Brazil and Bolivia south to Argentina and Chile. Found on lakes and marshes in open lowlands.
White-headed Steamerduck
Breeds across northern Canada in boreal and sub-Arctic lakes; winters on the Atlantic and Gulf coasts of North America.
Conservation Status
Black-headed Duck
White-headed Steamerduck
How to Tell Them Apart
Black-headed Duck
Male has distinctive jet-black head and neck, warm chestnut-brown back, and pale buff underparts; blue-grey bill with red base. Female is streaked brown above with pale supercilium and whitish underparts.
White-headed Steamerduck
Flightless. Males have white head and neck contrasting with dark gray-brown body; orange bill. Females brown with white facial markings and less contrasting head. Restricted to Chubut, Argentina coast.
About These Birds
Black-headed Duck
A small diving duck (~530 g) of South America, family Anatidae, and the sole member of genus Heteronetta. Inhabits freshwater marshes and lakes in Argentina, Bolivia, Brazil, Chile, and Uruguay. Unique among waterfowl as an obligate brood parasite, laying eggs in nests of coots and other waterbirds. Feeds on seeds and aquatic invertebrates. Least Concern.
White-headed Steamerduck
A large flightless steamerduck with grey body and an entirely white head in males, found only along the Patagonian coast of Chubut Province, Argentina. One of the rarest ducks in South America; range extends for only about 400 km of coastline.