Hawaiian Goose vs Black-headed Duck
Branta sandvicensis 对比 Heteronetta atricapilla
Side-by-Side Comparison
| 属性 | Hawaiian Goose | Black-headed Duck |
|---|---|---|
| 学名 | Branta sandvicensis | Heteronetta atricapilla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保护状况 | Near Threatened | Least Concern |
| 体长 | — | — |
| 翼展 | 72.8 cm (28.7 in) | 34.7 cm (13.7 in) |
| 体重 | 2150.0 g (75.84 oz) | 528.5 g (18.64 oz) |
| 食性 | Eats aquatic plants, algae, and grasses; upends in shallow water to graze submerged vegetation; diet … | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … |
| 产卵数 | 1-6 | 2 |
| Population Trend | — | — |
Habitat Comparison
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
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.
Black-headed Duck
Male gives a soft, raspy peeping note; female produces a muted quack. An obligate brood parasite with reduced vocalizations; subdued calls suit its secretive lifestyle among Argentine reeds.
Geographic Range & Migration
Hawaiian Goose
Breeds in sub-Arctic Canada; winters on large lakes and rivers from the Gulf of Mexico north to where water remains open.
Black-headed Duck
Resident in southern South America from southern Brazil and Bolivia south to Argentina and Chile. Found on lakes and marshes in open lowlands.
保护状况
Hawaiian Goose
Black-headed Duck
How to Tell Them Apart
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 …
Black-headed Duck
Male has distinctive jet-black head and neck, warm chestnut-brown back, and pale buff underparts; blue-grey bill with red base. Female is streaked brown above with pale supercilium and whitish underparts.
About These Birds
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。
Black-headed Duck
黑头鸭是南美洲的寄生性鸭子，不自己筑巢，而将卵产于其他水鸟（包括其他鸭类、䴙䴘、红鹭等）的巢中，由寄主孵化并抚育。分布于阿根廷、乌拉圭、智利和巴西南部。雄鸟头部黑色，体羽深褐色；雌鸟头部褐色。是唯一真正的全职巢寄生鸭类。