Laysan Duck vs Spotted Whistling-duck
Anas laysanensis 比較対象 Dendrocygna guttata
Side-by-Side Comparison
| 属性 | Laysan Duck | Spotted Whistling-duck |
|---|---|---|
| 学名 | Anas laysanensis | Dendrocygna guttata |
| 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) | 41.3 cm (16.3 in) |
| 体重 | 465.25 g (16.41 oz) | 677.5 g (23.90 oz) |
| 食性 | Dives for small fish, aquatic invertebrates, and amphibians; serrated bill grips prey; diet fish-heavy in … | Primarily herbivorous; grazes tundra grasses and sedges; winters on coastal marshes and farmland, switching to … |
| 一腹卵数 | 9-13 | 10-11 |
| 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.
Spotted Whistling-duck
Freshwater wetlands, rice fields, streams, and forest pools in New Guinea, Sulawesi, the Philippines, and Moluccas. Often found near forested rivers and seasonal swamps at low elevations.
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.
Spotted Whistling-duck
A musical, high whistle similar to other whistling-ducks. Call is softer and less far-carrying than White-faced or Black-bellied species. Given in flight and on water.
Geographic Range & Migration
Laysan Duck
Resident in West Africa from Senegal to Nigeria; inhabits rainforest streams and swamps. Sedentary and locally common.
Spotted Whistling-duck
Ranges widely across sub-Saharan Africa in open woodland and savanna. Largely sedentary with local seasonal movements to water.
保全状況
Laysan Duck
Spotted Whistling-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 …
Spotted Whistling-duck
Dark brown above; head and neck dark brown. Underparts heavily spotted white on dark brown ground, giving spotted appearance. Flanks with bold white spots. Pink-red bill and legs. Sexes similar.
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。
Spotted Whistling-duck
スポッテドウィスリングダックはインドネシア、フィリピン、パプアニューギニアに分布するツリーダックです。白い斑点のある褐色の羽毛が特徴で、夜間に特徴的な笛のような声でさえずります。熱帯の湿地、稲田、マングローブ林に生息し、草の種子や水草を採食します。