Black-headed Duck vs Torrent Duck
Heteronetta atricapilla compared with Merganetta armata
Side-by-Side Comparison
| Attribute | Black-headed Duck | Torrent Duck |
|---|---|---|
| Scientific Name | Heteronetta atricapilla | Merganetta armata |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 34.7 cm (13.7 in) | 32.7 cm (12.9 in) |
| Weight | 528.5 g (18.64 oz) | 366.875 g (12.94 oz) |
| Diet | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Filter-feeds on aquatic invertebrates and seeds; dabbles in shallow wetlands; diet more plant-based in winter … |
| Clutch Size | 2 | 3-4 |
| Population Trend | — | — |
Habitat Comparison
Torrent Duck
Fast-flowing clear Andean mountain rivers and torrents at 1,500–4,500 m from Venezuela south through Colombia, Ecuador, Peru, Bolivia, and Chile to Tierra del Fuego. Requires bouldered well-oxygenated rapids.
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.
Torrent Duck
A sharp, staccato 'pit' or 'wit' call. Males give a loud, ringing whistle. The Torrent Duck is a fast-flowing Andean river specialist; calls carry over powerful rapids.
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.
Torrent Duck
Breeds in the northern prairie pothole region; winters along both coasts of the United States and south to Mexico.
Conservation Status
Black-headed Duck
Torrent 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.
Torrent Duck
Striking sexual dimorphism. Males have white head with black stripes and red bill; dark back with rufous breast. Females gray above with rufous-cinnamon underparts. Stiff tail; specialized for fast-running rivers.
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.
Torrent Duck
A slim agile duck perfectly adapted to fast-flowing Andean rivers. Males are striking with a white-and-black-streaked head, red bill, and chestnut breast; females are rufous below. Forages by diving and swimming in violent rapids, holding on to boulders with strong claws. Monogamous with strong site fidelity.