Brent Goose vs African Pygmy-goose
Branta bernicla 比較対象 Nettapus auritus
Side-by-Side Comparison
| 属性 | Brent Goose | African Pygmy-goose |
|---|---|---|
| 学名 | Branta bernicla | Nettapus auritus |
| 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) | 29.9 cm (11.8 in) |
| 体重 | 1335.0 g (47.09 oz) | 272.5 g (9.61 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Filter-feeds on invertebrates and seeds; dabbles in shallow ponds; diet more plant-based outside spring breeding … |
| 一腹卵数 | 1-10 | 6-12 |
| 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.
African Pygmy-goose
Freshwater lakes, ponds, and rivers with floating water lilies and other aquatic vegetation across sub-Saharan Africa from Senegal to Tanzania. Nests in tree cavities near water. Highly dependent on water lily vegetation.
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.
African Pygmy-goose
Male produces a soft, wheezy whistle; female gives a quiet, duck-like quack. Pairs exchange rapid twittering notes during courtship on lily-covered African pools.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
African Pygmy-goose
Breeds across temperate to sub-Arctic Eurasia; winters in Africa, South Asia, and Southeast Asia.
保全状況
Brent Goose
African Pygmy-goose
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.
African Pygmy-goose
Tiny. Males have glossy dark green head with orange facial patch and ear spot; chestnut-orange flanks; white underparts; black and green back. Females duller with dark eye-stripe. Small yellow-green bill.
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。
African Pygmy-goose
アフリカンピグミーグースはアフリカ南部と東部に分布する小型の木巣性カモです。雄の緑と栗色の美しい羽毛と小さなサイズが特徴的です。水草が豊富な湖や沼地に生息し、蓮や水草の種子を主食とします。木の洞に営巣します。