Brent Goose vs White-headed Steamerduck
Branta bernicla 比較対象 Tachyeres leucocephalus
Side-by-Side Comparison
| 属性 | Brent Goose | White-headed Steamerduck |
|---|---|---|
| 学名 | Branta bernicla | Tachyeres leucocephalus |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Vulnerable |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | 55.0 cm (21.7 in) |
| 体重 | 1335.0 g (47.09 oz) | 3250.0 g (114.64 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | -- |
| 一腹卵数 | 1-10 | 3-6 |
| 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.
White-headed Steamerduck
Rocky coastal shores, sea channels, and sheltered bays along the Patagonian coast of Chubut Province, Argentina. Flightless; strictly coastal. Nests on rocky headlands. Very limited geographic range.
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.
White-headed Steamerduck
A deep, rattling call from Patagonian coastal habitat. VU status; calls similar to Magellanic Steamerduck but possibly subtly distinct. Vocalizations in wild remain understudied.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
White-headed Steamerduck
保全状況
Brent Goose
White-headed Steamerduck
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.
White-headed Steamerduck
Flightless. Males have white head and neck contrasting with dark gray-brown body; orange bill. Females brown with white facial markings and less contrasting head. Restricted to Chubut, Argentina coast.
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。
White-headed Steamerduck
チョエノスステームアーダックはアルゼンチン南部のチョエノス群島に固有の飛べないカモです。白い頭部と大きな体が特徴的です。沿岸の島嶼の岩礁地帯に生息し、貝類、甲殻類、海藻を採食します。フォークランドスティーマーダックに近縁です。