Black-headed Duck vs Torrent Duck
Heteronetta atricapilla 比較対象 Merganetta armata
Side-by-Side Comparison
| 属性 | Black-headed Duck | Torrent Duck |
|---|---|---|
| 学名 | Heteronetta atricapilla | Merganetta armata |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 34.7 cm (13.7 in) | 32.7 cm (12.9 in) |
| 体重 | 528.5 g (18.64 oz) | 366.875 g (12.94 oz) |
| 食性 | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Filter-feeds on aquatic invertebrates and seeds; dabbles in shallow wetlands; diet more plant-based in winter … |
| 一腹卵数 | 2 | 3-4 |
| Population Trend | — | — |
Habitat Comparison
Torrent Duck
Fast-flowing clear Andean mountain rivers and torrents at 1,500–4,500 m from Venezuela south through Colombia, Ecuador, Peru, Bolivia, and Chile to Tierra del Fuego. Requires bouldered well-oxygenated rapids.
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.
Torrent Duck
A sharp, staccato 'pit' or 'wit' call. Males give a loud, ringing whistle. The Torrent Duck is a fast-flowing Andean river specialist; calls carry over powerful rapids.
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.
Torrent Duck
Breeds in the northern prairie pothole region; winters along both coasts of the United States and south to Mexico.
保全状況
Black-headed Duck
Torrent 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.
Torrent Duck
Striking sexual dimorphism. Males have white head with black stripes and red bill; dark back with rufous breast. Females gray above with rufous-cinnamon underparts. Stiff tail; specialized for fast-running rivers.
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。
Torrent Duck
トレンツアイサはアンデス山脈の急流河川に生息する特殊なカモです。水流の速い清澄な渓流に適応しており、流れの中の岩の上を歩き回ります。魚、水生昆虫、甲殻類を捕食します。厳しい流れに適応した独特の生態を持ちます。