Swan Goose vs Brent Goose
Anser cygnoid 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Swan Goose | Brent Goose |
|---|---|---|
| 学名 | Anser cygnoid | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Endangered | Least Concern |
| 体長 | — | — |
| 翼開長 | 84.4 cm (33.2 in) | 63.9 cm (25.2 in) |
| 体重 | 3343.75 g (117.95 oz) | 1335.0 g (47.09 oz) |
| 食性 | Herbivore; grazes aquatic plants and grasses at wetland margins; takes invertebrates in spring; diet shifts … | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | 4-8 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Swan Goose
Breeds on steppe lakes, rivers, and meadows in Mongolia, Siberia, and northeastern China. Winters in eastern China's Yangtze River floodplain and coastal wetlands. Wild populations critically small.
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
Swan Goose
A deep, resonant 'honk'; less frequently heard than Greylag. The EN status reflects serious population decline; vocalizations are considered similar to Greylag Goose.
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.
Geographic Range & Migration
Swan Goose
Breeds in the tundra and boreal zones of Alaska and Canada; winters on the Pacific coast from British Columbia to California.
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Swan Goose
Brent Goose
How to Tell Them Apart
Swan Goose
Long neck with rich chestnut hindneck stripe. Forehead and crown dark brown; face and throat whitish. Upperparts grayish-brown; underparts pale. Long black bill. Pink legs. Ancestor of Chinese domestic geese.
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.
About These Birds
Swan Goose
サカツラガンはシベリア南東部と中国北東部に繁殖し、中国南部と朝鮮半島で越冬するガンです。細長い首と大きな嘴の根元の黒い模様が特徴的です。日本には稀に飛来します。湿地、草地、農地に生息し、草や農作物を採食します。
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。