Greater White-fronted Goose vs Ruddy Duck
Anser albifrons 比較対象 Oxyura jamaicensis
Side-by-Side Comparison
| 属性 | Greater White-fronted Goose | Ruddy Duck |
|---|---|---|
| 学名 | Anser albifrons | Oxyura jamaicensis |
| 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) | 27.9 cm (11.0 in) |
| 体重 | 2471.0 g (87.16 oz) | 586.6666666666666 g (20.69 oz) |
| 食性 | Dabbles for aquatic invertebrates, seeds, and plant material; diet shifts heavily toward invertebrates in breeding … | Dives for aquatic plant seeds, roots, and invertebrates in freshwater marshes. Uses stiff tail as … |
| 一腹卵数 | 3-9 | 5-15 |
| 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.
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.
Ruddy Duck
Male produces a mechanical, drumming bok-bok-bok staccato beat; female gives a harsh, nasal quack. The male's rapid drum-roll call on the bill during display is startlingly loud and distinctive.
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.
Ruddy Duck
Breeds across interior North America from western Canada south to Mexico. Winters on coasts and inland waters south to northern South America.
保全状況
Greater White-fronted Goose
Ruddy 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 …
Ruddy Duck
Breeding male has vivid rufous-chestnut body, black crown, white cheeks, and bright sky-blue bill; stiff tail often cocked upright. Female is dull brown with pale cheek crossed by single dark …
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。
Ruddy Duck
北米で繁殖し、中米・南米北部で越冬する小型の潜水ガモ（体長35〜43cm）。雄の繁殖羽は栗色の体に白い頬、青い嘴が特徴的。Oxyura jamaicensis（ルディダック）は特徴的な扇状の尾羽を立てる姿勢で知られる。北米原産だがヨーロッパに移入・定着し、近縁のフェルギネオウ・ホワイトヘッドダックとの交雑が問題となっている。Anatidae科。