Canvasback vs Brent Goose
Aythya valisineria 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Canvasback | Brent Goose |
|---|---|---|
| 学名 | Aythya valisineria | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 44.7 cm (17.6 in) | 63.9 cm (25.2 in) |
| 体重 | 1223.25 g (43.15 oz) | 1335.0 g (47.09 oz) |
| 食性 | Eats molluscs, crustaceans, and aquatic invertebrates; dives in coastal and freshwater habitats; diet dominated by … | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | 2-16 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Canvasback
Breeds on prairie potholes and boreal lakes across western North America. Winters on large open lakes, reservoirs, estuaries, and Chesapeake Bay. Sensitive to loss of prairie wetlands.
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.
Song & Call Comparison
Canvasback
Male produces a low, cooing purr; female gives a harsh, rolling quacking series. Males whisper-call in rolling, cooing notes during courtship; female's harsh quacking is emphatic on North American marshes.
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.
Geographic Range & Migration
Canvasback
Breeds in wooded wetlands of Canada and the northern United States; winters in the southern US and Central America.
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Canvasback
Brent Goose
How to Tell Them Apart
Canvasback
Males have rich chestnut-red head and neck; black breast; pale canvas-gray body; white flanks. Sloping forehead profile with dark red bill and red eye. Females gray-brown with reddish-brown head. Dimorphic …
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.
About These Birds
Canvasback
キャンバスバックは北米に分布する大型の潜水性カモです。雄は鮮やかな赤褐色の頭部と赤い目、白い体が特徴的です。内陸の湖や湿地に繁殖し、冬季には湾岸や大きな湖に集まります。イモチウキゴモ（Vallisneria）の塊茎を好んで潜って採食します。
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。