Black-headed Duck vs Blue Duck
Heteronetta atricapilla 比較対象 Hymenolaimus malacorhynchos
Side-by-Side Comparison
| 属性 | Black-headed Duck | Blue Duck |
|---|---|---|
| 学名 | Heteronetta atricapilla | Hymenolaimus malacorhynchos |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Endangered |
| 体長 | — | — |
| 翼開長 | 34.7 cm (13.7 in) | 45.6 cm (18.0 in) |
| 体重 | 528.5 g (18.64 oz) | 861.75 g (30.40 oz) |
| 食性 | 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 … |
| 一腹卵数 | 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.
保全状況
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
クロアタマカモはアルゼンチン・チリ・ウルグアイ・ブラジル南部の南アメリカ温帯湖沼・湿地に生息する托卵性のカモ（体長32〜35 cm）。雄は黒い頭と薄い茶色の体が特徴。他のカモ・コオット・ヒクイナの巣に托卵する。育雛しない数少ない水禽の一つ。
Blue Duck
ブルーダックはニュージーランド固有の希少なカモで、ニュージーランドの国鳥の候補の一つです。青灰色の羽毛と岩の間を縫うように飛ぶ能力が特徴的です。急流の清澄な渓流に生息し、水生昆虫を主食とします。