Brent Goose vs Smew
Branta bernicla 比較対象 Mergellus albellus
Side-by-Side Comparison
| 属性 | Brent Goose | Smew |
|---|---|---|
| 学名 | Branta bernicla | Mergellus albellus |
| 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) | 37.5 cm (14.8 in) |
| 体重 | 1335.0 g (47.09 oz) | 658.75 g (23.24 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for small fish, aquatic insects, and crustaceans in freshwater and coastal habitats. Uses serrated … |
| 一腹卵数 | 1-10 | 5-11 |
| 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.
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.
Smew
Male gives a soft, crow-like krr note; female produces a grating, rasping call. Both sexes are relatively quiet; the male's harsh, crow-like call is surprisingly low for such a small …
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Smew
Breeds in boreal forests of northern Europe and Siberia. Winters on large lakes and coasts from western Europe east to Japan and China.
保全状況
Brent Goose
Smew
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.
Smew
Male is largely white with black eye patch, black lines on back, and fine black lines on flanks creating a cracked-ice pattern. Female has chestnut-red head, white cheeks, and grey …
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。
Smew
ミコアイサはユーラシア北部の針葉樹林帯に繁殖し、東アジアで越冬する潜水性カモです。雄は白い体に黒い模様が美しいです。日本では冬鳥として全国の湖沼、池、河川に飛来します。木の洞に営巣し、魚、水生昆虫、甲殻類を潜って採食します。