Laysan Duck vs American Black Duck
Anas laysanensis 比較対象 Anas rubripes
Side-by-Side Comparison
| 属性 | Laysan Duck | American Black Duck |
|---|---|---|
| 学名 | Anas laysanensis | Anas rubripes |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Critically Endangered | Least Concern |
| 体長 | — | — |
| 翼開長 | 39.7 cm (15.6 in) | 53.4 cm (21.0 in) |
| 体重 | 465.25 g (16.41 oz) | 1211.25 g (42.73 oz) |
| 食性 | Dives for small fish, aquatic invertebrates, and amphibians; serrated bill grips prey; diet fish-heavy in … | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … |
| 一腹卵数 | 9-13 | 1-17 |
| Population Trend | — | — |
Habitat Comparison
Laysan Duck
Restricted to Laysan Island and Midway Atoll in the Hawaiian Islands. Inhabits the central hypersaline lagoon and surrounding vegetation. Feeds on brine shrimp and flies around the lagoon margin.
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.
Song & Call Comparison
Laysan Duck
Female gives a soft, muffled quacking series; male utters a quiet rasp. Extremely rare; the soft, unobtrusive quacking calls are seldom heard on the remote Laysan Island lagoon.
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.
Geographic Range & Migration
Laysan Duck
Resident in West Africa from Senegal to Nigeria; inhabits rainforest streams and swamps. Sedentary and locally common.
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
保全状況
Laysan Duck
American Black Duck
How to Tell Them Apart
Laysan Duck
Brown plumage mottled and streaked buff and dark brown. White eye-ring contrasts with dark face. Both sexes similar; females show reduced white eye ring. Iridescent speculum. Critically endangered; only on …
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 …
About These Birds
Laysan Duck
レイサンガモはハワイのレイサン島にのみ生息する極めて希少な固有種です。マガモから進化したと考えられており、翼に白い斑点があるのが特徴です。かつて絶滅の危機に瀕していましたが、保全活動により個体数が回復しています。飛翔能力は持ちますが、主に地上を歩いて採食します。
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。