Laysan Duck vs African Black Duck
Anas laysanensis 对比 Anas sparsa
Side-by-Side Comparison
| 属性 | Laysan Duck | African Black Duck |
|---|---|---|
| 学名 | Anas laysanensis | Anas sparsa |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保护状况 | Critically Endangered | Least Concern |
| 体长 | — | — |
| 翼展 | 39.7 cm (15.6 in) | 49.5 cm (19.5 in) |
| 体重 | 465.25 g (16.41 oz) | 996.8333333333334 g (35.16 oz) |
| 食性 | Dives for small fish, aquatic invertebrates, and amphibians; serrated bill grips prey; diet fish-heavy in … | Eats molluscs, crustaceans, and aquatic invertebrates; dives in coastal and freshwater habitats; diet heavier in … |
| 产卵数 | 9-13 | 4-9 |
| 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.
African Black Duck
Fast-flowing rocky rivers and streams, mountain gorges, and waterfalls from sea level to 4,000 m across sub-Saharan Africa from Ethiopia and Kenya south to the Cape. Requires clear turbulent water with boulders.
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.
African Black Duck
Produces a harsh, resonant quacking call; alarm is a loud, emphatic quack repeated rapidly. Both sexes call with strong quacking; pairs duet with synchronized calls along African rivers.
Geographic Range & Migration
Laysan Duck
Resident in West Africa from Senegal to Nigeria; inhabits rainforest streams and swamps. Sedentary and locally common.
African Black Duck
Resident across South and Southeast Asia, from India to southern China and the Philippines. Non-migratory in most of its range.
保护状况
Laysan Duck
African 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 …
African Black Duck
Dark blackish-brown plumage with bold white spots on back and scapulars. Iridescent blue-green speculum with white borders. Head dark with pale spots. Bill and legs dark gray. Sexes similar. Fast-flowing …
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。
African Black Duck
A medium-sized dark brown duck with white spots on the back, a dark bill, and orange legs. Found along fast-flowing rocky rivers and streams in Africa. Territorial and monogamous; pairs defend stretches of river. Related to Pacific Black Duck.