Brent Goose vs Tundra Swan
Branta bernicla 比較対象 Cygnus columbianus
Side-by-Side Comparison
| 属性 | Brent Goose | Tundra Swan |
|---|---|---|
| 学名 | Branta bernicla | Cygnus columbianus |
| 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) | 107.6 cm (42.4 in) |
| 体重 | 1335.0 g (47.09 oz) | 6675.0 g (235.45 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, aquatic plants, and invertebrates; filter-feeds in shallow water; diet becomes more invertebrate-heavy in … |
| 一腹卵数 | 1-10 | 3-6 |
| 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.
Tundra Swan
Breeds on Arctic tundra ponds and lakes in Alaska, Canada, and Siberia. Winters on coastal estuaries, shallow bays, agricultural fields, and freshwater lakes in North America, Europe, and eastern 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.
Tundra Swan
A high, bugling 'who-who-who' with a musical quality. North American subspecies (Whistling Swan) produces a higher-pitched call than European Bewick's Swan (Cygnus c. bewickii).
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Tundra Swan
Breeds in the northern Great Plains; winters along the Gulf Coast from Texas to Florida. Uses the Central and Mississippi flyways.
保全状況
Brent Goose
Tundra Swan
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.
Tundra Swan
All-white plumage; bill black with small yellow patch at base near eye. Neck shorter and rounder-headed than Trumpeter Swan. Juveniles grayish-brown. Bewick's race has more extensive yellow on bill.
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。
Tundra Swan
北極圏で繁殖し、北半球の温帯沿岸・湖沼で越冬するハクチョウ（体長115〜150cm）。純白の羽毛と黄と黒の嘴が特徴で、コハクチョウとも呼ばれる。Cygnus columbianus（コハクチョウ）は日本の越冬地として琵琶湖や北日本の湖沼が重要で、毎年何千羽もが越冬する壮観な光景が見られる。Anatidae科。