Brent Goose vs Magellanic Steamerduck
Branta bernicla 比較対象 Tachyeres pteneres
Side-by-Side Comparison
| 属性 | Brent Goose | Magellanic Steamerduck |
|---|---|---|
| 学名 | Branta bernicla | Tachyeres pteneres |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 52.2 cm (20.6 in) |
| 体重 | 1335.0 g (47.09 oz) | 4881.25 g (172.18 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Feeds on seeds, aquatic invertebrates, and plant matter; dabbles in wetlands; diet heavily invertebrate during … |
| 一腹卵数 | 1-10 | 4-8 |
| 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.
Magellanic Steamerduck
Rocky coastal shores, kelp-fringed channels, and sheltered bays of Patagonian Chile and Argentina. Flightless; confined to coastline. Nests on rocky shorelines. Uses wings to propel across water surface.
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.
Magellanic Steamerduck
A loud, rattling, staccato 'kik-kik-kik' that sounds like a steam engine — hence 'steamerduck'. The wings also produce a loud churring sound as they beat the water surface.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Magellanic Steamerduck
Breeds in the Arctic and sub-Arctic; winters on the open Pacific Ocean from British Columbia to Baja California.
保全状況
Brent Goose
Magellanic Steamerduck
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.
Magellanic Steamerduck
Heavy, flightless. Males gray with white eye-stripe and orange-yellow bill. Breast and flanks mottled rufous-brown. Females more brown with white eye-ring and olive-yellow bill. Wings used for steaming.
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。
Magellanic Steamerduck
フライトレスステームアーダックは南米最南端のパタゴニアと周辺島嶼に生息する飛べないカモです。大きな体と強い脚が特徴で、水面を蒸気船のように翼で漕いで移動します。沿岸の海藻、貝類、甲殻類を採食します。