Brent Goose vs Common Eider
Branta bernicla 比較対象 Somateria mollissima
Side-by-Side Comparison
| 属性 | Brent Goose | Common Eider |
|---|---|---|
| 学名 | Branta bernicla | Somateria mollissima |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Near Threatened |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 56.0 cm (22.0 in) |
| 体重 | 1335.0 g (47.09 oz) | 2042.8333333333333 g (72.06 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for blue mussels, clams, and crustaceans in shallow coastal waters. Swallows shellfish whole and … |
| 一腹卵数 | 1-10 | 2-7 |
| 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.
Common Eider
Male produces a loud, resonant ah-WOOO cooing; female gives a deep, guttural quacking series. The male's iconic moaning call echoes across North Atlantic coastlines; a classic seaduck sound.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Common Eider
Breeds on Arctic and subarctic coasts from the North Atlantic to the Pacific. Winters along coasts of northwestern Europe and eastern North America.
保全状況
Brent Goose
Common Eider
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.
Common Eider
Male is strikingly pied: white back, neck, and breast contrasting with black cap, belly, and flanks; nape washed pale lime-green. Female uniformly barred warm tawny-brown with darker streaks.
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。
Common Eider
北極圏から温帯の海岸で繁殖する大型の潜水ガモ（体長50〜71cm）。雄は白・黒の体に緑の後頭部が特徴的。Somateria mollissima（ホンケワタガモ）の雌は抱卵時に自分の胸の羽（エイダーダウン）を抜いて卵を覆い、これが世界最高の天然断熱材として知られる。Anatidae科。