Brent Goose vs New Zealand Merganser
Branta bernicla 比較対象 Mergus australis
Side-by-Side Comparison
| 属性 | Brent Goose | New Zealand Merganser |
|---|---|---|
| 学名 | Branta bernicla | Mergus australis |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Extinct |
| 体長 | — | — |
| 翼開長 | 63.9 cm (25.2 in) | — |
| 体重 | 1335.0 g (47.09 oz) | 898.0 g (31.68 oz) |
| 食性 | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … | Extinct; historically dived for fish and aquatic invertebrates in New Zealand freshwater streams. Diet inferred … |
| 一腹卵数 | 1-10 | -- |
| 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.
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.
New Zealand Merganser
Extinct (EX). No recordings exist. This flightless New Zealand merganser likely gave grunting, nasal calls similar to the Red-breasted Merganser based on skull morphology and taxonomy.
Geographic Range & Migration
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
New Zealand Merganser
Formerly endemic to South Island and Stewart Island, New Zealand. Extinct since the 1900s.
保全状況
Brent Goose
New Zealand Merganser
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.
New Zealand Merganser
Both sexes were dark brown overall; male had greenish-black gloss on head with slight crest, whitish barring on wings; female paler brown with rufous-tinged head and whitish throat.
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。
New Zealand Merganser
オークランド諸島のマージャンサー。絶滅種。ニュージーランドのオークランド島に生息していたが、外来のブタや猫などの捕食者の影響で1905年以降に絶滅。