Black-headed Duck vs Knob-billed Duck
Heteronetta atricapilla 比較対象 Sarkidiornis melanotos
Side-by-Side Comparison
| 属性 | Black-headed Duck | Knob-billed Duck |
|---|---|---|
| 学名 | Heteronetta atricapilla | Sarkidiornis melanotos |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 34.7 cm (13.7 in) | 64.2 cm (25.3 in) |
| 体重 | 528.5 g (18.64 oz) | 1817.5 g (64.11 oz) |
| 食性 | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … | Dabbles for seeds and aquatic invertebrates; diet shifts toward invertebrate prey in spring breeding season; … |
| 一腹卵数 | 2 | 6-20 |
| Population Trend | — | — |
Habitat Comparison
Knob-billed Duck
Freshwater lakes, marshes, floodplains, and forested wetlands across sub-Saharan Africa and South and Southeast Asia from India to southern China. Nests in large tree hollows near water.
Song & Call Comparison
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.
Knob-billed Duck
A low, grunting 'wuk' or soft, nasal 'krank'. Similar to Comb Duck in call quality. Generally quiet; calls are not loud or distinctive compared to other large African waterfowl.
Geographic Range & Migration
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.
Knob-billed Duck
Breeds on sub-Arctic tundra; winters on the Atlantic coast of North America from Labrador to Florida and the Gulf Coast.
保全状況
Black-headed Duck
Knob-billed Duck
How to Tell Them Apart
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.
Knob-billed Duck
Males have white head with black spots; iridescent dark blue-black back and wings; white underparts with gray flanks. Large black fleshy knob atop bill. Females smaller, brown, and lack the …
About These Birds
Black-headed Duck
クロアタマカモはアルゼンチン・チリ・ウルグアイ・ブラジル南部の南アメリカ温帯湖沼・湿地に生息する托卵性のカモ（体長32〜35 cm）。雄は黒い頭と薄い茶色の体が特徴。他のカモ・コオット・ヒクイナの巣に托卵する。育雛しない数少ない水禽の一つ。
Knob-billed Duck
ノブビルダックはアフリカ、南アジア、南米に広く分布するカモです。雄の嘴の根元にある肉質のコブが特徴的です。木の洞に営巣し、湿地、川、池に生息します。季節的な移動をすることがあります。水草、種子、農作物を採食します。