Madagascar Pochard vs Brent Goose
Aythya innotata 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Madagascar Pochard | Brent Goose |
|---|---|---|
| 学名 | Aythya innotata | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Critically Endangered | Least Concern |
| 体長 | — | — |
| 翼開長 | 37.4 cm (14.7 in) | 63.9 cm (25.2 in) |
| 体重 | 685.0 g (24.16 oz) | 1335.0 g (47.09 oz) |
| 食性 | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal and freshwater habitats. | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | 6-10 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Madagascar Pochard
Restricted to Lake Matsaborimena in the highlands of northern Madagascar at about 1,500 m altitude. Uses deep-water mountain lakes with aquatic vegetation. Critically Endangered; tiny wild population.
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.
Song & Call Comparison
Madagascar Pochard
Critically Endangered; produces a soft, Aythya-like purring and grating quacking. Calls are not well-documented; likely similar to closely related Ferruginous Duck based on phylogeny.
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.
Geographic Range & Migration
Madagascar Pochard
Breeds across the northern boreal zone of Canada and Alaska; winters along the Pacific and Atlantic coasts of North America.
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Madagascar Pochard
Brent Goose
How to Tell Them Apart
Madagascar Pochard
Males have brown head and neck; dark brown back; pale gray flanks with white undertail. White eye. Blue-gray bill. Females browner with pale face patch and brown eye. Critically endangered; …
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.
About These Birds
Madagascar Pochard
マダガスカルポチャードはマダガスカル固有の極めて希少な潜水性カモです。長年にわたり野生絶滅と考えられていましたが、2006年に北部の湖で再発見されました。深水の湖に生息し、水生植物を潜って採食します。現在は飼育繁殖プログラムで個体数回復が図られています。
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。