Black-headed Duck vs Ruddy Shelduck
Heteronetta atricapilla compared with Tadorna ferruginea
Side-by-Side Comparison
| Attribute | Black-headed Duck | Ruddy Shelduck |
|---|---|---|
| Scientific Name | Heteronetta atricapilla | Tadorna ferruginea |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 34.7 cm (13.7 in) | 71.1 cm (28.0 in) |
| Weight | 528.5 g (18.64 oz) | 1318.3333333333333 g (46.50 oz) |
| Diet | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Feeds on seeds, plant material, and aquatic invertebrates; dabbles in wetlands; diet varies between seasons … |
| Clutch Size | 2 | 8-16 |
| Population Trend | — | — |
Habitat Comparison
Ruddy Shelduck
Steppe lakes, river valleys, inland saline and freshwater wetlands from southeastern Europe and North Africa east through Central Asia to China and Mongolia. Winters on lakes and rivers in South and Southeast Asia.
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.
Ruddy Shelduck
A loud, resonant bugling 'aakh' from males; females give a rapid cackling 'kak-kak-kak'. Call carries far across open Asian steppe and river valleys.
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.
Ruddy Shelduck
Breeds in wetlands across Eurasia; winters from sub-Saharan Africa to South and Southeast Asia. Broad wintering distribution.
Conservation Status
Black-headed Duck
Ruddy Shelduck
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.
Ruddy Shelduck
Warm orange-rufous overall plumage; paler buffy head. Males have narrow black neck collar in breeding season. Black tail and primaries. White wing coverts and iridescent green speculum visible in flight. …
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.
Ruddy Shelduck
A large orange-brown shelduck with a pale buff head, black neck ring (male only), white wing patches, and bright green speculum. Widespread from Morocco and southeastern Europe east to China. Sacred to Buddhists in Tibet. Nests in burrows, rock crevices, and ruins.