Brent Goose vs Spotted Whistling-duck
Branta bernicla 比較対象 Dendrocygna guttata
Side-by-Side Comparison
| 属性 | Brent Goose | Spotted Whistling-duck |
|---|---|---|
| 学名 | Branta bernicla | Dendrocygna guttata |
| 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) | 41.3 cm (16.3 in) |
| 体重 | 1335.0 g (47.09 oz) | 677.5 g (23.90 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Primarily herbivorous; grazes tundra grasses and sedges; winters on coastal marshes and farmland, switching to … |
| 一腹卵数 | 1-10 | 10-11 |
| 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.
Spotted Whistling-duck
Freshwater wetlands, rice fields, streams, and forest pools in New Guinea, Sulawesi, the Philippines, and Moluccas. Often found near forested rivers and seasonal swamps at low elevations.
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.
Spotted Whistling-duck
A musical, high whistle similar to other whistling-ducks. Call is softer and less far-carrying than White-faced or Black-bellied species. Given in flight and on water.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Spotted Whistling-duck
Ranges widely across sub-Saharan Africa in open woodland and savanna. Largely sedentary with local seasonal movements to water.
保全状況
Brent Goose
Spotted Whistling-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.
Spotted Whistling-duck
Dark brown above; head and neck dark brown. Underparts heavily spotted white on dark brown ground, giving spotted appearance. Flanks with bold white spots. Pink-red bill and legs. Sexes similar.
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。
Spotted Whistling-duck
スポッテドウィスリングダックはインドネシア、フィリピン、パプアニューギニアに分布するツリーダックです。白い斑点のある褐色の羽毛が特徴で、夜間に特徴的な笛のような声でさえずります。熱帯の湿地、稲田、マングローブ林に生息し、草の種子や水草を採食します。