Brent Goose vs Cotton Pygmy-goose
Branta bernicla 比較対象 Nettapus coromandelianus
Side-by-Side Comparison
| 属性 | Brent Goose | Cotton Pygmy-goose |
|---|---|---|
| 学名 | Branta bernicla | Nettapus coromandelianus |
| 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) | 31.7 cm (12.5 in) |
| 体重 | 1335.0 g (47.09 oz) | 343.5 g (12.12 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Feeds on aquatic invertebrates, seeds, and plant material; dabbles in shallow water; invertebrate diet peaks … |
| 一腹卵数 | 1-10 | 6-18 |
| 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.
Cotton Pygmy-goose
Freshwater lakes, ponds, slow rivers, and rice paddies with aquatic vegetation from India east through Southeast Asia, China, and New Guinea to northern and eastern Australia. Nests in tree holes near 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.
Cotton Pygmy-goose
Male emits a rapid, clucking chatter resembling a toy rattle; female responds with soft, muffled quacks. In flight both sexes produce a distinctive whistling wing-beat.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Cotton Pygmy-goose
Breeds in northern Eurasia; winters in the tropics of Africa and Asia. Migratory; routes cross through the Middle East.
保全状況
Brent Goose
Cotton 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.
Cotton Pygmy-goose
Males white below and white-faced with dark green crown and collar; black back with iridescent green gloss; white wing bar conspicuous in flight. Females brown-gray with pale supercilium. Tiny; perches …
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。
Cotton Pygmy-goose
コットンティールは南アジアから東南アジア、オーストラリアにかけて分布する小型のカモです。白い羽毛と緑色の翼の縁が特徴的で、陸上より水上での生活が得意なカモです。蓮の葉の上を歩くことができます。水草が豊富な湖、池、水田に生息します。