Brent Goose vs White-backed Duck
Branta bernicla 比較対象 Thalassornis leuconotus
Side-by-Side Comparison
| 属性 | Brent Goose | White-backed Duck |
|---|---|---|
| 学名 | Branta bernicla | Thalassornis leuconotus |
| 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) | 33.3 cm (13.1 in) |
| 体重 | 1335.0 g (47.09 oz) | 704.6666666666666 g (24.86 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | -- |
| 一腹卵数 | 1-10 | 4-10 |
| 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.
White-backed Duck
Freshwater lakes, ponds, and swamps with abundant floating aquatic vegetation, especially water lilies, in sub-Saharan Africa and Madagascar. Prefers shallow sheltered water with emergent vegetation for cover.
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.
White-backed Duck
Soft, low whistles and hissing sounds. The White-backed Duck is relatively quiet compared to whistling-ducks. Alarm call is a low 'peep'. Mostly heard at night.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
White-backed Duck
保全状況
Brent Goose
White-backed Duck
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.
White-backed Duck
Heavily mottled and barred brown and buff overall. Diagnostic white back patch visible in flight. Head brown with whitish face and chin. Stiff tail held erect. Sexes similar; stiff-tail diving …
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。
White-backed Duck
ホワイトバックドダックはアフリカ南部と東部に分布する潜水性カモです。背中の白い斑と斑模様の羽毛が特徴です。水草が豊富な湖や湿地に生息し、主にキイトモ（Potamogeton）の塊茎を潜って採食します。繁殖期には水面に浮かぶ巣を作ります。