Ring-necked Duck vs Brent Goose
Aythya collaris 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Ring-necked Duck | Brent Goose |
|---|---|---|
| 学名 | Aythya collaris | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | — | — |
| 翼開長 | 39.0 cm (15.4 in) | 63.9 cm (25.2 in) |
| 体重 | 825.5 g (29.12 oz) | 1335.0 g (47.09 oz) |
| 食性 | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal water; diet dominated by benthic … | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | 6-14 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Ring-necked Duck
Breeds on boreal lakes and bogs in North America from Alaska and Canada south to the northern United States. Winters on freshwater lakes, reservoirs, and marshes across the southern United States, Mexico, and Caribbean.
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
Ring-necked Duck
Male produces a low, purring wheeze; female gives a harsh, rolling quack. The purring male call is understated; found on North American freshwater lakes; female calls are emphatic and nasal.
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
Ring-necked Duck
Breeds in western Arctic Canada and Alaska; winters along the Pacific coast from Alaska to Baja California.
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Ring-necked Duck
Brent Goose
How to Tell Them Apart
Ring-necked Duck
Males black back and breast; gray flanks with white vertical mark near breast. Iridescent dark purple head with subtle chestnut neck ring. Bill blue-gray with white ring near tip. Females …
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
Ring-necked Duck
リングネックドダックは北米に繁殖する潜水性カモです。雄は黒い頭部と胸部、灰色の体、嘴の白いリングが特徴的です。森林に囲まれた湖や池を好み、水草の塊茎、種子、水生昆虫を潜って採食します。冬季には南部の湖や河川に大群で渡ります。
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。