Black-headed Duck vs Spectacled Eider
Heteronetta atricapilla comparado con Somateria fischeri
Side-by-Side Comparison
| Atributo | Black-headed Duck | Spectacled Eider |
|---|---|---|
| Nombre científico | Heteronetta atricapilla | Somateria fischeri |
| Orden | Anseriformes | Anseriformes |
| Familia | Anatidae | Anatidae |
| Estado de conservación | Least Concern | Near Threatened |
| Longitud | — | — |
| Envergadura | 34,7 cm (13.7 in) | 49,2 cm (19.4 in) |
| Peso | 528,5 g (18.64 oz) | 1443,75 g (50.93 oz) |
| Dieta | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Dives for bivalves, crustaceans, and aquatic insects in shallow Arctic coastal and freshwater habitats. Insects … |
| Tamaño de la puesta | 2 | 1-9 |
| 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.
Spectacled Eider
Male gives a low, melodious aah-ooo cooing; female produces a guttural, grunting call. The male's ghostly, organ-like cooing call carries across Arctic tundra ponds in the breeding season.
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.
Spectacled Eider
Breeds on coastal tundra of western and northern Alaska. Winters along the Bering Sea coast from Alaska to Kamchatka. Largely sedentary.
Estado de conservación
Black-headed Duck
Spectacled Eider
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.
Spectacled Eider
Male has white back and black breast with pale sage-green head framed by large white goggle-like spectacles edged black. Female mottled tawny-brown with faint spectacle outline.
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.
Spectacled Eider
El eider del espectáculo es un gran eider ártico con el macho de cabeza verdosa y un espectacular parche ocular blanco con contorno negro que recuerda a unas gafas. Cría en la tundra del norte de Alaska y Siberia, y pasa la mayor parte del invierno en el mar de Bering. Está clasificado como amenazado, con declives de población en Alaska.