Brent Goose vs Ashy-headed Goose
Branta bernicla 比較対象 Chloephaga poliocephala
Side-by-Side Comparison
| 属性 | Brent Goose | Ashy-headed Goose |
|---|---|---|
| 学名 | Branta bernicla | Chloephaga poliocephala |
| 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) | 69.1 cm (27.2 in) |
| 体重 | 1335.0 g (47.09 oz) | 1779.25 g (62.76 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats grasses, seeds, and aquatic invertebrates; grazes upland pastures and dabbles in wetlands; diet varies … |
| 一腹卵数 | 1-10 | 4-6 |
| 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.
Ashy-headed Goose
Temperate forests, forest clearings, and lake margins in southern Chile and Patagonian Argentina. Partially migratory; breeds in beech forest zones and winters on open grasslands farther north.
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.
Ashy-headed Goose
A whistled 'seeeeu' from males and a lower cackling from females. Ashy-headed Goose calls carry across Andean foothills and Patagonian grassland habitats.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Ashy-headed Goose
Inhabits wetlands and flooded grasslands across South and Southeast Asia, from India to Indonesia. Largely resident year-round.
保全状況
Brent Goose
Ashy-headed Goose
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.
Ashy-headed Goose
Gray head and neck contrast with chestnut breast and rufous-barred flanks. Back brown; belly white. White wing patch in flight with iridescent green speculum. Yellow-orange legs. Sexes similar but females …
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。
Ashy-headed Goose
アスウェイウィンガンはアンデス山脈の湿地と草原に生息するガン科鳥類です。灰色の頭部と白黒の翼が特徴的です。チリとアルゼンチンの南部に分布し、草地、農地、湿地に生息します。草や農作物を採食します。