Brent Goose vs Barrow's Goldeneye
Branta bernicla 比較対象 Bucephala islandica
Side-by-Side Comparison
| 属性 | Brent Goose | Barrow's Goldeneye |
|---|---|---|
| 学名 | Branta bernicla | Bucephala islandica |
| 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) | 44.3 cm (17.4 in) |
| 体重 | 1335.0 g (47.09 oz) | 838.0 g (29.56 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Dives for crustaceans, aquatic insects, and molluscs in mountain lakes and coastal bays. Diet similar … |
| 一腹卵数 | 1-10 | 6-14 |
| 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.
Barrow's Goldeneye
Male produces a whistled, nasal kaow-kaow call; female gives a harsh quacking series. The male's wheezy, double call differs from Common Goldeneye; heard on western North American lakes.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Barrow's Goldeneye
Breeds in Iceland, western Canada, and locally the western United States. Winters on coasts and lakes of the Pacific Northwest and eastern Canada.
保全状況
Brent Goose
Barrow's Goldeneye
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.
Barrow's Goldeneye
Male has iridescent purple-black head with crescent-shaped white facial patch; white body with black scapulars bearing bold white spots. Female grey with brown head, white collar; head rounder than Common …
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。
Barrow's Goldeneye
アナチダエ科の中型の洞営巣ガモ（約840g）で、雄は紫色光沢の頭部と三日月形の白い顔斑を持つ。北米西部とアイスランドの山地湖近くで繁殖；沿岸の湾で越冬する。無脊椎動物と小魚を潜って食べる。営巣に大きな木の洞が必要な軽度懸念種。