Amsterdam Duck vs Black-headed Duck
Anas marecula so với Heteronetta atricapilla
Side-by-Side Comparison
| Thuộc Tính | Amsterdam Duck | Black-headed Duck |
|---|---|---|
| Tên Khoa Học | Anas marecula | Heteronetta atricapilla |
| Bộ | Anseriformes | Anseriformes |
| Họ | Anatidae | Anatidae |
| Tình Trạng Bảo Tồn | Extinct | Least Concern |
| Chiều Dài | — | — |
| Chiều Dài Sải Cánh | — | 34,7 cm (13.7 in) |
| Khối Lượng | 289,5 g (10.21 oz) | 528,5 g (18.64 oz) |
| Chế Độ Ăn | Extinct Auckland Islands Merganser; fed on freshwater fish and aquatic invertebrates in streams; inferred from … | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … |
| Số Trứng | -- | 2 |
| Population Trend | — | — |
Habitat Comparison
Amsterdam Duck
Historically restricted to Amsterdam Island in the southern Indian Ocean. Now extinct. Presumably inhabited the island's freshwater sources and coastal areas.
Song & Call Comparison
Amsterdam Duck
Extinct (EX). No recordings exist. As an Anas relative, likely gave a typical duck-like quacking call; male may have had a soft whistled note similar to other island teals.
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.
Geographic Range & Migration
Amsterdam Duck
Breeds on sub-Antarctic islands of the South Indian Ocean; disperses across the Southern Ocean when not nesting.
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.
Tình Trạng Bảo Tồn
Amsterdam Duck
Black-headed Duck
How to Tell Them Apart
Amsterdam Duck
Extinct Amsterdam Island duck known only from bones and a single historical description. Presumably brown plumage typical of Anas dabbling ducks. Flightless or near-flightless; extirpated by introduced predators.
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.
About These Birds
Amsterdam Duck
An extinct diving duck known from subfossil remains discovered on Amsterdam Island in the southern Indian Ocean. Flightless or nearly flightless; probably resembled the Laysan Duck in size. Went extinct around 1800 following human colonization of the island.
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.