Brent Goose vs Ruddy-headed Goose
Branta bernicla 比較対象 Chloephaga rubidiceps
Side-by-Side Comparison
| 属性 | Brent Goose | Ruddy-headed Goose |
|---|---|---|
| 学名 | Branta bernicla | Chloephaga rubidiceps |
| 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) | 65.1 cm (25.6 in) |
| 体重 | 1335.0 g (47.09 oz) | 1756.8333333333333 g (61.97 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | -- |
| 一腹卵数 | 1-10 | 3-8 |
| 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.
Ruddy-headed Goose
Breeds on open tussock grasslands and moorland in Tierra del Fuego and the Falkland Islands. Mainland wintering population on Patagonian grasslands now critically small. Falkland Islands population relatively stable.
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.
Ruddy-headed Goose
A high, whistled 'whee' from males and a cackling rattle from females. Calls similar to Ashy-headed Goose. Falkland Islands population; calls in open coastal grassland.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Ruddy-headed Goose
保全状況
Brent Goose
Ruddy-headed 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.
Ruddy-headed Goose
Distinctive rufous-brown head and neck; body barred rufous and black above; underparts buff-white finely barred. Orange-yellow legs. White wing patches in flight. Compact; sexes similar. Falklands and Patagonia.
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。
Ruddy-headed Goose
ルディーヘッドガンは南米南端のパタゴニアとフォークランド諸島に分布する小型のガン科鳥類です。雄は赤褐色の頭部と白い腹が特徴的です。草地に生息し、草を採食します。フォークランド諸島の繁殖個体群は激減しており、絶滅危惧種です。