Brent Goose vs Marbled Duck
Branta bernicla 比較対象 Marmaronetta angustirostris
Side-by-Side Comparison
| 属性 | Brent Goose | Marbled Duck |
|---|---|---|
| 学名 | Branta bernicla | Marmaronetta angustirostris |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Near Threatened |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 40.1 cm (15.8 in) |
| 体重 | 1335.0 g (47.09 oz) | 422.5 g (14.90 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for molluscs, crustaceans, and small fish; diet dominated by hard-shelled benthic invertebrates in coastal … |
| 一腹卵数 | 1-10 | 5-20 |
| 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.
Marbled Duck
Shallow densely vegetated freshwater and brackish marshes, rice paddies, and lagoons in the Mediterranean basin, Middle East, and Central Asia. Winters in Africa and South Asia. Dependent on emergent wetland vegetation.
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.
Marbled Duck
Male gives a low, guttural chuckling; female produces a nasal, rattling quack. Calls are relatively quiet for a duck; the chuckling male call is unusual among Eurasian and North African …
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Marbled Duck
Breeds in the high Arctic; winters on the open Atlantic Ocean and along coastlines from Labrador to the Gulf of Mexico.
保全状況
Brent Goose
Marbled 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.
Marbled Duck
Pale sandy-buff plumage with bold white spots throughout; distinctive marbled pattern. Dark eye patch forming mask. Pale face and throat. No iridescent speculum. Gray bill; gray legs. Sexes similar. Mediterranean …
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。
Marbled Duck
マーブルダックは地中海地方から中央アジアにかけて分布する潜水性カモです。白と褐色のまだら模様の羽毛が特徴で、嘴が細長いです。浅い湿地、葦原、塩湖に生息し、水草、藻類、無脊椎動物を採食します。生息地の減少で個体数が大幅に減少しています。