Brent Goose vs South African Shelduck
Branta bernicla 比較対象 Tadorna cana
Side-by-Side Comparison
| 属性 | Brent Goose | South African Shelduck |
|---|---|---|
| 学名 | Branta bernicla | Tadorna cana |
| 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) | 69.0 cm (27.2 in) |
| 体重 | 1335.0 g (47.09 oz) | 1323.6666666666667 g (46.69 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, aquatic plants, and invertebrates; dabbles in shallow water; diet more invertebrate-heavy in breeding … |
| 一腹卵数 | 1-10 | 4-11 |
| 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.
South African Shelduck
Inland freshwater and saline lakes, pans, dams, and rivers across southern Africa, primarily on the South African plateau, Lesotho, and Namibia. Nests in burrows dug by aardvark. Highly terrestrial for a shelduck.
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.
South African Shelduck
Male gives a whistled 'wheeu'; female gives a harsh, descending cackle. Calls from South African wetlands and vleis. Sexual dimorphism in call is strong.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
South African Shelduck
Breeds in subarctic Eurasia and winters in sub-Saharan Africa, the Indian subcontinent, and Southeast Asia.
保全状況
Brent Goose
South African 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.
South African Shelduck
Males have gray head and neck; rufous-brown body with white wing coverts and green speculum. Females similar but with white facial markings around bill and eye. Body rich rufous-chestnut. Endemic …
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。
South African Shelduck
ケープシェルダックは南アフリカに固有のカモです。雄はオレンジ色の体と灰色の頭部が特徴的です。ダム、川、湿地、農地に生息し、草、種子、無脊椎動物を採食します。南アフリカで最もよく見られる大型カモの一つです。