Brent Goose vs Red-breasted Goose
Branta bernicla 比較対象 Branta ruficollis
Side-by-Side Comparison
| 属性 | Brent Goose | Red-breasted Goose |
|---|---|---|
| 学名 | Branta bernicla | Branta ruficollis |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Vulnerable |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 69.1 cm (27.2 in) |
| 体重 | 1335.0 g (47.09 oz) | 1253.25 g (44.21 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Grazes grasses, seeds, and aquatic plants; introduced to many wetlands; upends in shallow water for … |
| 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.
Red-breasted Goose
Breeds on river-terrace tundra in northwestern Siberia, often near Peregrine or Rough-legged Buzzard nests for protection. Winters on agricultural steppes and lake margins around the Black Sea and Caspian Sea.
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.
Red-breasted Goose
A high-pitched, rapid 'kik-kik-kik' call. More vocal during migration; flocks give constant chattering. Considered a more squeaky, high-pitched call than other Branta geese.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Red-breasted Goose
Breeds in Arctic and subarctic tundra in North America; winters along both US coasts and interior wetlands south to Central America.
保全状況
Brent Goose
Red-breasted Goose
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.
Red-breasted Goose
Unmistakable; vivid chestnut-red patch on face and breast bordered by white stripes. Black crown, back, wings, and belly. White flank stripe and undertail. Compact and striking. Sexes similar.
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。
Red-breasted Goose
アカノドガンはロシア北部のツンドラで繁殖し、ルーマニアや中央アジアで越冬する美しいガンです。赤褐色の喉と頬、白と黒の模様が特徴的です。草地や農地で採食します。絶滅危惧種に指定されており、越冬地での生息地破壊が主な脅威です。