Laysan Duck vs Spotted Whistling-duck
Anas laysanensis 对比 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 |
| 保护状况 | Critically Endangered | Least Concern |
| 体长 | — | — |
| 翼展 | 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 … |
| 产卵数 | 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.
保护状况
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
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。
Spotted Whistling-duck
斑树鸭是东南亚和西南太平洋的树鸭，分布于印度尼西亚、菲律宾、巴布亚新几内亚及澳大利亚北部。体羽深褐色，胸部和腹部具白色斑点，嘴灰黑色。栖息于热带雨林的湖泊、河流和湿地，以水生植物、种子和无脊椎动物为食，在树洞中营巢。