Brent Goose vs Ruddy Shelduck
Branta bernicla 比較対象 Tadorna ferruginea
Side-by-Side Comparison
| 属性 | Brent Goose | Ruddy Shelduck |
|---|---|---|
| 学名 | Branta bernicla | Tadorna ferruginea |
| 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) | 71.1 cm (28.0 in) |
| 体重 | 1335.0 g (47.09 oz) | 1318.3333333333333 g (46.50 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Feeds on seeds, plant material, and aquatic invertebrates; dabbles in wetlands; diet varies between seasons … |
| 一腹卵数 | 1-10 | 8-16 |
| 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.
Ruddy Shelduck
Steppe lakes, river valleys, inland saline and freshwater wetlands from southeastern Europe and North Africa east through Central Asia to China and Mongolia. Winters on lakes and rivers in South and Southeast Asia.
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.
Ruddy Shelduck
A loud, resonant bugling 'aakh' from males; females give a rapid cackling 'kak-kak-kak'. Call carries far across open Asian steppe and river valleys.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Ruddy Shelduck
Breeds in wetlands across Eurasia; winters from sub-Saharan Africa to South and Southeast Asia. Broad wintering distribution.
保全状況
Brent Goose
Ruddy Shelduck
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.
Ruddy Shelduck
Warm orange-rufous overall plumage; paler buffy head. Males have narrow black neck collar in breeding season. Black tail and primaries. White wing coverts and iridescent green speculum visible in flight. …
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。
Ruddy Shelduck
東ヨーロッパ・中央アジア・中国の河川・湖沼・草原に生息するカモ（体長58〜70cm）。鮮やかなオレンジ色の体と白い翼が特徴的。Tadorna ferruginea（アカツクシガモ）は土手や崖の穴、岩の割れ目に営巣し、日本にも冬季に迷鳥として飛来することがある。Anatidae科。