Brent Goose vs Crested Shelduck
Branta bernicla 对比 Tadorna cristata
Side-by-Side Comparison
| 属性 | Brent Goose | Crested Shelduck |
|---|---|---|
| 学名 | Branta bernicla | Tadorna cristata |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保护状况 | Least Concern | Critically Endangered |
| 体长 | — | — |
| 翼展 | 63.9 cm (25.2 in) | 59.8 cm (23.5 in) |
| 体重 | 1335.0 g (47.09 oz) | 1235.0 g (43.56 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Possibly extinct; Crested Shelduck fed on seeds, aquatic plants, and invertebrates near East Asian wetlands; … |
| 产卵数 | 1-10 | 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.
Crested Shelduck
Historically known from coastal Korea, Siberia, and possibly Japan. Habitat preferences poorly known; specimens were collected near coasts and rivers. Possibly extinct.
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.
Crested Shelduck
Critically endangered; last confirmed sightings in 1971. No vocalizations reliably recorded. Presumed similar to related shelducks based on phylogeny but effectively unknown.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Crested Shelduck
Breeds across the Palearctic; winters from West Africa to South Africa. Uses the western and central Palearctic–African flyways.
保护状况
Brent Goose
Crested 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.
Crested Shelduck
Critically rare; known from few specimens. Males dark green head with bushy crest; black and white body with chestnut flanks. Females have white facial markings and brown-barred body. Possibly extinct; …
About These Birds
Brent Goose
黑雁是小型海雁，繁殖于北极苔原，越冬于温带沿海地区。全身黑色，颈部有白色斑纹，腹部浅色或深色（因亚种而异）。以海草（大叶藻）和潮间带植物为食，高度依赖沿海湿地。在欧洲和北美分布有多个亚种，其中部分亚种数量因大叶藻减少而受到威胁。
Crested Shelduck
冠麻鸭是已知的最后一个可靠标本记录于20世纪初的朝鲜半岛，此后再无确认记录，可能已灭绝。外形与赤麻鸭相似，但雄鸟头顶具绿色羽冠。曾繁殖于朝鲜半岛和中国北部，越冬于中国南部。灭绝原因可能与栖息地丧失和过度猎捕有关，目前仍被列为极危物种（可能已灭绝）。