Brent Goose vs Common Shelduck
Branta bernicla 比較対象 Tadorna tadorna
Side-by-Side Comparison
| 属性 | Brent Goose | Common Shelduck |
|---|---|---|
| 学名 | Branta bernicla | Tadorna tadorna |
| 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) | 62.8 cm (24.7 in) |
| 体重 | 1335.0 g (47.09 oz) | 1035.5 g (36.53 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Eats seeds, leaves, and aquatic invertebrates; dabbles in shallow water; diet broadly omnivorous and varies … |
| 一腹卵数 | 1-10 | 3-18 |
| 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.
Common Shelduck
Coastal estuaries, mudflats, saltmarshes, sand dunes, and inland saline lakes from northwest Europe east across Eurasia to China. Winters mainly on tidal estuaries and coastal wetlands. Nests in burrows.
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.
Common Shelduck
Male gives a whistled 'wheee'; female gives a cackling series of rapid nasal 'ak-ak-ak' notes. One of the most sexually dimorphic calls of any shelduck species.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Common Shelduck
Breeds in Siberian tundra; winters in eastern and southern Africa, and in South and Southeast Asia. Trans-hemispheric migrant.
保全状況
Brent Goose
Common Shelduck
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.
Common Shelduck
White body with dark green head, broad chestnut breastband, and black scapular stripes. Red bill with basal knob in males. Green speculum and black wingtips. Underparts white with black belly …
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。
Common Shelduck
西ヨーロッパから中央アジアにかけての塩性干潟・砂浜に生息するカモ（体長58〜67cm）。白・黒・緑・赤褐色の鮮やかな羽模様と雄の赤いこぶ付き嘴が特徴的。Tadorna tadorna（ツクシガモ）は地上の穴に営巣し、ウミホタルなどの微小な生物を泥の中からこし取る。日本では迷鳥として稀に観察される。Anatidae科。