Greater White-fronted Goose vs Knob-billed Duck
Anser albifrons 比較対象 Sarkidiornis melanotos
Side-by-Side Comparison
| 属性 | Greater White-fronted Goose | Knob-billed Duck |
|---|---|---|
| 学名 | Anser albifrons | Sarkidiornis melanotos |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 81.6 cm (32.1 in) | 64.2 cm (25.3 in) |
| 体重 | 2471.0 g (87.16 oz) | 1817.5 g (64.11 oz) |
| 食性 | Dabbles for aquatic invertebrates, seeds, and plant material; diet shifts heavily toward invertebrates in breeding … | -- |
| 一腹卵数 | 3-9 | 6-20 |
| Population Trend | — | — |
Habitat Comparison
Greater White-fronted Goose
Breeds on Arctic and subarctic tundra and peatlands. Winters on estuaries, agricultural fields, freshwater marshes, and flooded meadows across Europe, Asia, and North America. One of the most widespread geese.
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
Greater White-fronted Goose
A loud, laughing 'kow-lyuk' or musical 'wah-wah'. Gives a distinctive high-pitched yodeling quality lacking in Greylag. Highly vocal in large winter flocks.
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
Greater White-fronted Goose
Breeds in the potholes region of the northern Great Plains; winters in the southern United States and along the Gulf Coast.
Knob-billed Duck
保全状況
Greater White-fronted Goose
Knob-billed Duck
How to Tell Them Apart
Greater White-fronted Goose
Brown-gray body with white forehead patch bordered by white band at bill base. Underparts with bold irregular black bars on belly. Orange bill; orange-yellow legs. Juveniles lack white front and …
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
Greater White-fronted Goose
北極圏で繁殖し、温帯で越冬する大型のガン（体長64〜81cm）。成鳥は白い額と黒い腹部の横縞が特徴。Anser albifrons（マガン）は東アジア、ヨーロッパ、北米の広大な農地や湿地で越冬する。日本では宮城県伊豆沼などが重要な越冬地で、数万羽が集まる壮観な光景が見られる。Anatidae科。
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。