Black-headed Duck vs New Zealand Merganser
Heteronetta atricapilla مقارنةً بـ Mergus australis
Side-by-Side Comparison
| السمة | Black-headed Duck | New Zealand Merganser |
|---|---|---|
| الاسم العلمي | Heteronetta atricapilla | Mergus australis |
| الرتبة | Anseriformes | Anseriformes |
| الفصيلة | Anatidae | Anatidae |
| حالة الحفاظ | Least Concern | Extinct |
| الطول | — | — |
| طول الجناح | 34,7 cm (13.7 in) | — |
| الوزن | 528,5 g (18.64 oz) | 898,0 g (31.68 oz) |
| النظام الغذائي | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Extinct; historically dived for fish and aquatic invertebrates in New Zealand freshwater streams. Diet inferred … |
| عدد البيض في الوضع | 2 | -- |
| 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.
New Zealand Merganser
Extinct (EX). No recordings exist. This flightless New Zealand merganser likely gave grunting, nasal calls similar to the Red-breasted Merganser based on skull morphology and taxonomy.
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.
New Zealand Merganser
Formerly endemic to South Island and Stewart Island, New Zealand. Extinct since the 1900s.
حالة الحفاظ
Black-headed Duck
New Zealand Merganser
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.
New Zealand Merganser
Both sexes were dark brown overall; male had greenish-black gloss on head with slight crest, whitish barring on wings; female paler brown with rufous-tinged head and whitish throat.
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.
New Zealand Merganser
An extinct flightless or near-flightless merganser (~900 g) of family Anatidae, endemic to the subantarctic Auckland Islands of New Zealand. Inhabited forested riverine habitats and fed on freshwater fish and invertebrates. Exterminated by hunting and predation from introduced mammals; last reliably recorded in 1902 and declared Extinct.