Laysan Duck vs American Black Duck
Anas laysanensis 对比 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 |
| 保护状况 | Critically Endangered | Least Concern |
| 体长 | — | — |
| 翼展 | 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 … |
| 产卵数 | 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.
保护状况
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
莱岛鸭是世界上最濒危的鸭类之一，仅分布于夏威夷莱岛群岛的莱桑岛。这种小型鸭子由于长期与世隔绝，几乎完全失去了飞行能力。其种群曾一度减少至仅约12只，经过保护努力数量有所恢复。它主要以昆虫、无脊椎动物和藻类为食，面临外来物种入侵的严峻威胁。
American Black Duck
A large dark brown dabbling duck closely resembling a very dark female Mallard, with purple speculum, yellowish-olive bill in males, and orange legs. Common in eastern North America. Hybridizes freely with Mallard; pure populations declining in the interior.