Brent Goose vs Falkland Steamerduck
Branta bernicla 比較対象 Tachyeres brachypterus
Side-by-Side Comparison
| 属性 | Brent Goose | Falkland Steamerduck |
|---|---|---|
| 学名 | Branta bernicla | Tachyeres brachypterus |
| 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) | 49.0 cm (19.3 in) |
| 体重 | 1335.0 g (47.09 oz) | 3799.0 g (134.01 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, sedge shoots, and aquatic invertebrates; dabbles in ponds and marshes; diet varies with … |
| 一腹卵数 | 1-10 | 4-12 |
| 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.
Falkland Steamerduck
Exclusive to rocky coasts, sheltered coves, kelp beds, and sea inlets of the Falkland Islands. Flightless; strictly coastal. One of the few bird species entirely endemic to the Falkland Islands.
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.
Falkland Steamerduck
Similar to Magellanic Steamerduck in call quality — harsh, rattling, mechanical. Falkland Island birds' vocalizations adapted for stormy, windswept coastal habitat.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Falkland Steamerduck
Breeds in subarctic boreal ponds of Alaska and Canada; winters coastally from Alaska to California and on the Gulf Coast.
保全状況
Brent Goose
Falkland 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.
Falkland Steamerduck
Flightless; males gray with white supercilium and orange bill. Breast grayish-brown; flanks with brown mottling. Females brown with white eye-ring. Yellow-olive bill. Endemic to Falkland Islands.
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。
Falkland Steamerduck
フォークランドスティーマーダックはフォークランド諸島に固有の飛べないカモです。大きな体と短い翼が特徴で、水面を翼で漕いで移動します。沿岸の浅海、岩礁地帯に生息し、貝類、甲殻類、海藻を採食します。