Brent Goose vs Blue-billed Teal
Branta bernicla 比較対象 Spatula hottentota
Side-by-Side Comparison
| 属性 | Brent Goose | Blue-billed Teal |
|---|---|---|
| 学名 | Branta bernicla | Spatula hottentota |
| 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) | 29.4 cm (11.6 in) |
| 体重 | 1335.0 g (47.09 oz) | 269.2 g (9.50 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Feeds on seeds, aquatic plants, and invertebrates; filter-feeds in shallow water; broadly omnivorous and seasonally … |
| 一腹卵数 | 1-10 | 5-12 |
| 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.
Blue-billed Teal
Freshwater lakes, marshes, pans, and flooded grasslands across sub-Saharan Africa from Senegal and Sudan south to the Cape. Nomadic; follows seasonal rains. Common but easily overlooked among reed beds.
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.
Blue-billed Teal
Male utters a soft, teal-like peep; female gives a muted quack. Pairs call quietly in dense papyrus; soft contact calls help birds maintain proximity in thick African marsh vegetation.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Blue-billed Teal
Breeds in Arctic and subarctic Eurasia; winters at sea in the North Atlantic and from western Europe to eastern Africa.
保全状況
Brent Goose
Blue-billed Teal
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.
Blue-billed Teal
Small; males have pale blue-gray bill contrasting with brown-gray body. Head finely spotted; underparts barred brown and white. Males show powder-blue forewing in flight. Females browner. African marsh species.
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。
Blue-billed Teal
A small dark teal with blue-grey bill and legs, brown-streaked plumage, and fine pale spotting on the flanks. The most widespread teal in sub-Saharan Africa. Found on freshwater lakes and marshes. Highly nomadic; follows seasonal rainfall. Swims low in the water like a pochard.