Baer's Pochard vs Brent Goose
Aythya baeri 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Baer's Pochard | Brent Goose |
|---|---|---|
| 学名 | Aythya baeri | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Critically Endangered | Least Concern |
| 体長 | — | — |
| 翼開長 | 40.4 cm (15.9 in) | 63.9 cm (25.2 in) |
| 体重 | 707.25 g (24.95 oz) | 1335.0 g (47.09 oz) |
| 食性 | Dives for molluscs and aquatic invertebrates; diet dominated by hard-shelled benthic prey in coastal shallow-water … | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | 6-13 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Baer's Pochard
Breeds on lakes and rivers in boreal forests of eastern Siberia and northeastern China. Winters on freshwater lakes and wetlands in eastern and southeastern Asia. Critically Endangered; tiny remaining population.
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
Baer's Pochard
Male gives a low, grating wheeze; female produces a harsh quacking series. Calls resemble Tufted Duck but slightly softer; among the rarest duck calls in East Asia due to its …
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
Baer's Pochard
Breeds in Arctic Canada and Alaska; winters at sea off both US coasts and in the Great Lakes during migration.
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Baer's Pochard
Brent Goose
How to Tell Them Apart
Baer's Pochard
Males have dark glossy greenish-black head; chestnut breast; white flanks and undertail. White eye. Females brown with chestnut breast and pale face patch. White wing stripe in flight. Critically endangered …
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
Baer's Pochard
バエルのハジロはロシア東部と中国北東部で繁殖し、南アジアで越冬する潜水性カモです。雄は緑光沢のある黒い頭部と白い目が特徴的です。絶滅危惧種に指定されており、越冬地での狩猟圧力と繁殖地の湿地破壊が主な脅威です。
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。