Black-headed Duck vs Blue Duck
Heteronetta atricapilla comparado con Hymenolaimus malacorhynchos
Side-by-Side Comparison
| Atributo | Black-headed Duck | Blue Duck |
|---|---|---|
| Nombre científico | Heteronetta atricapilla | Hymenolaimus malacorhynchos |
| Orden | Anseriformes | Anseriformes |
| Familia | Anatidae | Anatidae |
| Estado de conservación | Least Concern | Endangered |
| Longitud | — | — |
| Envergadura | 34,7 cm (13.7 in) | 45,6 cm (18.0 in) |
| Peso | 528,5 g (18.64 oz) | 861,75 g (30.40 oz) |
| Dieta | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Eats aquatic invertebrates, seeds, and plant material; dabbles in shallow fresh water; invertebrate diet peaks … |
| Tamaño de la puesta | 2 | 5-6 |
| Population Trend | — | — |
Habitat Comparison
Blue Duck
Fast-flowing clear turbulent mountain rivers and streams in pristine native forest at 300–1,500 m in both main islands of New Zealand. Requires undisturbed riparian habitat with abundant aquatic invertebrates.
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.
Blue Duck
A soft, musical whistle from fast-flowing South Island rivers. Call is a clear 'whio' — giving the bird its Maori name. Also gives a soft, reedy 'squeak'. Endangered; rarely heard.
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.
Blue Duck
Breeds on open prairie wetlands of the Great Plains; winters in shallow estuaries and marshes along the Gulf of Mexico.
Estado de conservación
Black-headed Duck
Blue 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.
Blue Duck
Distinctive slate-blue-gray plumage; breast spotted with chestnut-brown in both sexes. Pale bill with flexible pink lobes at tip. Chestnut eye. Sexes similar; adapted to fast-flowing mountain streams in New Zealand.
About These Birds
Black-headed Duck
El pato cabeza negra es un pequeño pato buceador (~530 g) de América del Sur, familia Anatidae, y el único miembro del género Heteronetta. Tiene la cabeza negra en el macho y cuerpo marrón. Parásita de nido obligada: pone sus huevos en los nidos de otras aves acuáticas, especialmente fochas y pollas de agua. Habita en lagos y lagunas con vegetación emergente de Argentina, Bolivia, Brasil, Chile, Paraguay y Uruguay. No cría su propia cría nunca.
Blue Duck
El pato de pico azul es un pato azulado endémico de Nueva Zelanda, que habita en rápidos ríos de montaña de ambas islas principales.