Laysan Duck vs African Black Duck
Anas laysanensis 比較対象 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 |
| 保全状況 | Critically Endangered | Least Concern |
| 体長 | — | — |
| 翼開長 | 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 | -- | -- |
| 一腹卵数 | 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.
保全状況
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
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。
African Black Duck
アフリカンブラックダックはサハラ以南のアフリカの急流河川に生息する特殊なカモです。暗褐色の羽毛と白い斑点が特徴で、水流の速い清澄な渓流を好みます。繁殖期には縄張り意識が強く、ペアで生活します。急流の水生昆虫や甲殻類を主食とします。