Brent Goose vs Coscoroba Swan
Branta bernicla 比較対象 Coscoroba coscoroba
Side-by-Side Comparison
| 属性 | Brent Goose | Coscoroba Swan |
|---|---|---|
| 学名 | Branta bernicla | Coscoroba coscoroba |
| 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) | 84.2 cm (33.1 in) |
| 体重 | 1335.0 g (47.09 oz) | 4200.0 g (148.15 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, aquatic plants, and invertebrates; dabbles and upends in shallow water; diet more invertebrate-heavy … |
| 一腹卵数 | 1-10 | 4-9 |
| 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.
Coscoroba Swan
Freshwater lakes, marshes, lagoons, and flooded grasslands from southern Brazil through Uruguay, Chile, and Argentina to Tierra del Fuego. Partially migratory; moves northward in winter. Nests in reedy margins.
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.
Coscoroba Swan
A bugling, honking 'coscoroba' call — giving the species its onomatopoeic name. Loud and far-carrying. Less commonly heard than northern hemisphere swans.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Coscoroba Swan
Breeds in western North American prairies and parklands; winters in California, the Southwest, and northern Mexico.
保全状況
Brent Goose
Coscoroba Swan
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.
Coscoroba Swan
Entirely white plumage except black wingtips visible in flight. Bright red bill and red legs and feet. Red eye-ring. More goose-like than true swans. Juvenile has brownish wash. 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。
Coscoroba Swan
コスコロバはコウノトリに近縁とも言われる南米固有のハクチョウに似た大型水鳥です。白い羽毛と赤い嘴・脚が特徴的です。南米南部の湿地、湖、河口に生息し、水草、藻類、種子を採食します。コスコロバ属の唯一の種です。