Black-headed Duck vs Andean Duck
Heteronetta atricapilla compared with Oxyura ferruginea
Side-by-Side Comparison
| Attribute | Black-headed Duck | Andean Duck |
|---|---|---|
| Scientific Name | Heteronetta atricapilla | Oxyura ferruginea |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 34.7 cm (13.7 in) | 31.4 cm (12.4 in) |
| Weight | 528.5 g (18.64 oz) | 800.75 g (28.25 oz) |
| Diet | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Dives for aquatic invertebrates and plant seeds in Andean lakes and marshes. Diet similar to … |
| Clutch Size | 2 | 6-10 |
| Population Trend | — | — |
Habitat Comparison
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.
Andean Duck
Male gives a rapid, staccato drumming display call; female produces a nasal, quacking rattle. The male's mechanical drumming is similar to Ruddy Duck; echoes across Andean high-altitude lakes.
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.
Andean Duck
Resident in the Andes of Colombia, Ecuador, Peru, Bolivia, and northwestern Argentina. Found on high-altitude lakes above 3,000 m.
Conservation Status
Black-headed Duck
Andean Duck
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.
Andean Duck
Male is dark chestnut-rufous overall with black head, white cheeks tinged grey, and deep blue bill. Female is dark brownish with pale cheeks divided by a dark bar; similar to …
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.
Andean Duck
A stocky stiff-tailed duck (~800 g) of family Anatidae inhabiting high-altitude Andean lakes and wetlands from Colombia to Argentina. Males are rich chestnut with a blue bill during the breeding season. Dives for aquatic plants and invertebrates in cold Andean waters. Least Concern; formerly considered conspecific with Ruddy Duck but now recognized as a distinct species.