American Black Duck vs Torrent Duck
Anas rubripes 比較対象 Merganetta armata
Side-by-Side Comparison
| 属性 | American Black Duck | Torrent Duck |
|---|---|---|
| 学名 | Anas rubripes | Merganetta armata |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 53.4 cm (21.0 in) | 32.7 cm (12.9 in) |
| 体重 | 1211.25 g (42.73 oz) | 366.875 g (12.94 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Filter-feeds on aquatic invertebrates and seeds; dabbles in shallow wetlands; diet more plant-based in winter … |
| 一腹卵数 | 1-17 | 3-4 |
| Population Trend | — | — |
Habitat Comparison
American Black Duck
Freshwater and brackish wetlands in eastern North America from Atlantic Canada south along the coast to Georgia. Breeds in northern bogs and wetlands. Winters on coastal marshes, estuaries, and freshwater lakes.
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
American Black Duck
Female produces a loud, deep quacking series; male gives a low, raspy grunt. Voice is deeper and huskier than a Mallard; pairs call powerfully across northeastern North American wetlands.
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
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
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
American Black Duck
Torrent Duck
How to Tell Them Apart
American Black Duck
Sooty dark brown body; head and neck paler buff with dark streaking. Iridescent purple speculum without white border. Males have yellow-green bill; females olive with orange blotches. Silvery underwings in …
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
American Black Duck
北米東部の湿地、沼、河川に生息するカモ（体長53〜61cm）。全体的に暗褐色でマガモの雌に似るが、嘴の色や翼鏡の色が異なる。Anas rubripes（アメリカクロガモ）は海岸の塩性湿地から内陸の淡水域まで幅広く利用し、マガモとの雑種が多く観察される。Anatidae科。
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。