African Black Duck vs Hawaiian Goose
Anas sparsa 对比 Branta sandvicensis
Side-by-Side Comparison
| 属性 | African Black Duck | Hawaiian Goose |
|---|---|---|
| 学名 | Anas sparsa | Branta sandvicensis |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保护状况 | Least Concern | Near Threatened |
| 体长 | — | — |
| 翼展 | 49.5 cm (19.5 in) | 72.8 cm (28.7 in) |
| 体重 | 996.8333333333334 g (35.16 oz) | 2150.0 g (75.84 oz) |
| 食性 | Eats molluscs, crustaceans, and aquatic invertebrates; dives in coastal and freshwater habitats; diet heavier in … | Eats aquatic plants, algae, and grasses; upends in shallow water to graze submerged vegetation; diet … |
| 产卵数 | 4-9 | 1-6 |
| Population Trend | — | — |
Habitat Comparison
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.
Hawaiian Goose
Volcanic slopes, lava flows, coastal grasslands, and shrublands on Maui, Hawai'i, and Kauai. Adapted to rocky terrain with reduced toe webbing. Introduced to other Hawaiian islands. Avoids dense forest.
Song & Call Comparison
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.
Hawaiian Goose
A soft, low 'moo-moo' — the murmuring call gives the Nene its Hawaiian name. Also gives honking calls in flight. Less vocal than Canada Goose; distinctive murmuring quality.
Geographic Range & Migration
African Black Duck
Resident across South and Southeast Asia, from India to southern China and the Philippines. Non-migratory in most of its range.
Hawaiian Goose
Breeds in sub-Arctic Canada; winters on large lakes and rivers from the Gulf of Mexico north to where water remains open.
保护状况
African Black Duck
Hawaiian Goose
How to Tell Them Apart
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 …
Hawaiian Goose
Buff-tan neck with black and white channeled furrows. Crown and face black; hindneck black. Body gray-brown above; underparts pale with buff breast. Reduced webbing on feet. Sexes similar. State bird …
About These Birds
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.
Hawaiian Goose
夏威夷雁（奈内雁）是夏威夷的州鸟，也是世界上最稀有的雁类之一。特化于夏威夷熔岩地带生活，脚趾间蹼减退，适于在崎岖地面行走。曾因引入哺乳动物捕食和栖息地破坏而濒临灭绝，经人工繁育和再引入计划，数量已从20世纪50年代的不足30只恢复至2000余只。