Brent Goose vs Radjah Shelduck
Branta bernicla 比較対象 Radjah radjah
Side-by-Side Comparison
| 属性 | Brent Goose | Radjah Shelduck |
|---|---|---|
| 学名 | Branta bernicla | Radjah radjah |
| 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) | 54.0 cm (21.3 in) |
| 体重 | 1335.0 g (47.09 oz) | 883.5 g (31.16 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | -- |
| 一腹卵数 | 1-10 | 6-15 |
| 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.
Radjah Shelduck
Mangroves, tidal mudflats, tropical coastal wetlands, and freshwater lagoons in New Guinea and the tropical north of Australia (Queensland, Northern Territory, Western Australia). Nests in tree hollows near water.
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.
Radjah Shelduck
A loud, rattling 'radjah-radjah' or repeated cackling 'rak-rak-rak'. Calls from tropical Australian and New Guinea wetlands. Name is partly onomatopoeic.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Radjah Shelduck
保全状況
Brent Goose
Radjah 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.
Radjah Shelduck
White head and body with chestnut breastband and white-spotted chestnut scapulars. Pink bill and legs. Iridescent green speculum with white bar visible in flight. Sexes similar. Australasian mangrove specialist.
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。
Radjah Shelduck
A medium-sized elegant shelduck with white body plumage, chestnut breast band, dark green back, and pinkish-red bill and legs. Found in coastal mangroves, mudflats, and tropical wetlands of New Guinea and northern Australia. Calls with a loud raspy rattling sound.