American Black Duck vs Hardhead
Anas rubripes 比較対象 Aythya australis
Side-by-Side Comparison
| 属性 | American Black Duck | Hardhead |
|---|---|---|
| 学名 | Anas rubripes | Aythya australis |
| 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) | 42.7 cm (16.8 in) |
| 体重 | 1211.25 g (42.73 oz) | 803.75 g (28.35 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Dives for molluscs, crustaceans, and aquatic invertebrates in coastal habitats; diet shifts between invertebrate types … |
| 一腹卵数 | 1-17 | 6-18 |
| 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.
Hardhead
Deep freshwater lakes, rivers, and reservoirs across Australia and New Guinea. Nomadic in Australia, following seasonal inland flooding. Prefers deep water with submerged aquatic plants.
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.
Hardhead
Male produces a deep, purring wheeze; female gives a grating quacking series. Calls closely resemble Common Pochard; the female's harsh notes carry far across Australian freshwater lakes.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Hardhead
Breeds in northern prairie potholes; winters along the Pacific coast of North America from British Columbia to Baja California.
保全状況
American Black Duck
Hardhead
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 …
Hardhead
Males dark chocolate-brown with white undertail and flanks. White eye conspicuous. Blue-gray bill with white band and black tip. Females similar but brown with brown eye. Bold white wing stripe …
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。
Hardhead
オーストラリアンホワイトアイはオーストラリアとニュージーランドに分布する潜水性カモです。雄は栗色の頭部と赤い目が特徴的です。水草が豊富な深い湿地や湖に生息し、水に潜って水草の塊茎や根を採食します。オーストラリアでは比較的普通に見られる種です。