Brent Goose vs Goosander
Branta bernicla 比較対象 Mergus merganser
Side-by-Side Comparison
| 属性 | Brent Goose | Goosander |
|---|---|---|
| 学名 | Branta bernicla | Mergus merganser |
| 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) | 54.2 cm (21.3 in) |
| 体重 | 1335.0 g (47.09 oz) | 1488.0 g (52.49 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for fish, especially salmon and trout, in rivers and lakes. Also takes frogs, crustaceans, … |
| 一腹卵数 | 1-10 | 4-22 |
| 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.
Goosander
Male gives a harsh, crow-like karrr call; female produces a guttural, grunting series. Both sexes produce loud, nasal calls; the male's harsh croaking is a distinctive winter river sound.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Goosander
Breeds across boreal forests of North America, Europe, and Asia. Winters on coasts and large rivers south to the Mediterranean and South Asia.
保全状況
Brent Goose
Goosander
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.
Goosander
Male has dark green iridescent head, salmon-pink suffused white body, and black back; red serrated bill. Female has rufous-brown head with neat white chin patch, grey body, and pinkish-buff breast.
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。
Goosander
カワアイサはユーラシアと北米の淡水域に広く分布する大型の潜水性カモです。雄は緑色の頭部と白い体、赤い鋸状の嘴が特徴的です。日本では冬鳥として全国の河川や湖に飛来します。魚を潜って捕食します。木の洞や岩の割れ目に営巣します。