Mauritius Duck vs Brent Goose
Anas theodori 比較対象 Branta bernicla
Side-by-Side Comparison
| 属性 | Mauritius Duck | Brent Goose |
|---|---|---|
| 学名 | Anas theodori | Branta bernicla |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Extinct | Least Concern |
| 体長 | — | — |
| 翼開長 | — | 63.9 cm (25.2 in) |
| 体重 | — | 1335.0 g (47.09 oz) |
| 食性 | -- | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| 一腹卵数 | -- | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Mauritius Duck
Historically restricted to the Mascarene Islands (Mauritius and Réunion) in the Indian Ocean. Now extinct. Presumably inhabited freshwater wetlands and coastal areas before human colonization.
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
Mauritius Duck
Extinct (EX). No recordings exist. As a small island Anas duck, likely produced a quiet quacking call. Closest living relatives among insular Indian Ocean teals give soft, nasal notes.
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
Mauritius Duck
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
保全状況
Mauritius Duck
Brent Goose
How to Tell Them Apart
Mauritius Duck
Extinct Mascarene duck known only from subfossil bones. Plumage unrecorded; presumably brown dabbling duck plumage typical of Anas. Likely flightless or near-flightless; extirpated after European settlement of Mauritius.
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
Mauritius Duck
An extinct duck known from subfossil bones found on Mauritius and Réunion. Closely related to the Grey Teal. Went extinct after European settlement of the Mascarene Islands in the 17th century due to hunting and introduced predators.
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。