Brent Goose vs White-headed Duck
Branta bernicla 比較対象 Oxyura leucocephala
Side-by-Side Comparison
| 属性 | Brent Goose | White-headed Duck |
|---|---|---|
| 学名 | Branta bernicla | Oxyura leucocephala |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Endangered |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 29.7 cm (11.7 in) |
| 体重 | 1335.0 g (47.09 oz) | 705.0 g (24.87 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for aquatic invertebrates, seeds, and plant roots in Mediterranean and Central Asian wetlands. Critically … |
| 一腹卵数 | 1-10 | 3-10 |
| Population Trend | — | — |
Habitat Comparison
Brent Goose
Breeds on high-Arctic tundra; winters on estuaries, coastal mudflats, saltmarshes, and sea-grass beds along Atlantic and Pacific coastlines. One of the most strictly coastal wintering geese.
Song & Call Comparison
Brent Goose
A low, guttural 'rronk' or 'ronk-ronk' from flocks. Soft nasal calls in feeding groups. A subtle, understated call for a goose — less loud than most Anser geese.
White-headed Duck
Male produces a mechanical, rapid bill-drumming; female gives a harsh, grating quack. The drumming staccato display is the same pattern as other Oxyura stiff-tails; heard on Eurasian steppe lakes.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
White-headed Duck
Breeds in Spain, Turkey, central Asia, and Mongolia. Winters in the Mediterranean, the Middle East, and northern India. Globally endangered.
保全状況
Brent Goose
White-headed Duck
How to Tell Them Apart
Brent Goose
Small; mostly black head, neck, and breast. Small white neck-patch on adults. Back dark brownish-gray; belly pale gray to white depending on subspecies. White undertail coverts. Sexes similar.
White-headed Duck
Male has entirely white head with small black crown patch, rich chestnut-brown body, and large bulbous powder-blue bill. Female is brown with pale whitish face divided by dark streak across …
About These Birds
Brent Goose
北極圏で繁殖し、北半球の海岸で越冬する小型のガン（体長55〜66cm）。黒い頭・首・胸に短い白い首輪が特徴。Branta bernicla（コクガン）は主にアマモなどの海草を食べ、干潟や浅い入り江を好む。日本でも北海道・東北の海岸で越冬する姿が見られ、個体数は比較的少ない。Anatidae科。
White-headed Duck
カオジロオキアミガモは地中海地方から中央アジアにかけて分布する絶滅危惧種のカモです。雄の白い頭部と青い嘴が特徴的です。水草が豊富な浅い湖や池に生息し、水草の種子、塊茎、無脊椎動物を潜って採食します。生息地の減少と外来種との交雑が脅威です。