Brent Goose vs Hartlaub's Duck
Branta bernicla 比較対象 Pteronetta hartlaubii
Side-by-Side Comparison
| 属性 | Brent Goose | Hartlaub's Duck |
|---|---|---|
| 学名 | Branta bernicla | Pteronetta hartlaubii |
| 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) | 53.4 cm (21.0 in) |
| 体重 | 1335.0 g (47.09 oz) | 910.0 g (32.10 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, aquatic invertebrates, and plant matter; dabbles in ponds and marshes; diet more invertebrate-heavy … |
| 一腹卵数 | 1-10 | 7-11 |
| 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.
Hartlaub's Duck
Tropical rainforest streams, forest pools, and shaded swamps from Guinea and Sierra Leone east through the Congo Basin to Uganda and western Kenya. Requires undisturbed riverine forest with shaded 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.
Hartlaub's Duck
A low, nasal 'quack' and soft 'kek-kek'. Generally quieter than other perching ducks. Calls from dense Central and West African rainforest where it is rarely observed.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Hartlaub's Duck
Breeds in wetlands across Eurasia; winters from Africa and the Middle East to South and Southeast Asia.
保全状況
Brent Goose
Hartlaub's 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.
Hartlaub's Duck
Dark chocolate-brown body; white patches at side of head distinctive. Males have dark blue frontal shield extending from bill. Wings show pale blue-gray inner forewing. Legs gray. West African forest …
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。
Hartlaub's Duck
ハートラウブダックは西アフリカの森林に生息するカモです。青みがかった嘴と暗褐色の羽毛が特徴的です。熱帯雨林内の河川、沼地、森林の池に生息し、植物の種子、果実、無脊椎動物を採食します。アフリカ固有の珍しいカモです。