Laysan Duck vs Brent Goose
Anas laysanensis so với Branta bernicla
Side-by-Side Comparison
| Thuộc Tính | Laysan Duck | Brent Goose |
|---|---|---|
| Tên Khoa Học | Anas laysanensis | Branta bernicla |
| Bộ | Anseriformes | Anseriformes |
| Họ | Anatidae | Anatidae |
| Tình Trạng Bảo Tồn | Critically Endangered | Least Concern |
| Chiều Dài | — | — |
| Chiều Dài Sải Cánh | 39,7 cm (15.6 in) | 63,9 cm (25.2 in) |
| Khối Lượng | 465,25 g (16.41 oz) | 1335,0 g (47.09 oz) |
| Chế Độ Ăn | -- | Primarily herbivorous; grazes aquatic plants, grasses, and sedges; swans upend in shallow water for submerged … |
| Số Trứng | 9-13 | 1-10 |
| Population Trend | — | — |
Habitat Comparison
Môi Trường Sống Chung
Laysan Duck only
Không
Brent Goose only
Không
Laysan Duck
Restricted to Laysan Island and Midway Atoll in the Hawaiian Islands. Inhabits the central hypersaline lagoon and surrounding vegetation. Feeds on brine shrimp and flies around the lagoon margin.
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
Laysan Duck
Female gives a soft, muffled quacking series; male utters a quiet rasp. Extremely rare; the soft, unobtrusive quacking calls are seldom heard on the remote Laysan Island lagoon.
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
Laysan Duck
Brent Goose
Breeds across boreal and subarctic Canada and Alaska; winters in the southern United States, Mexico, and Central America.
Tình Trạng Bảo Tồn
Laysan Duck
Brent Goose
How to Tell Them Apart
Laysan Duck
Brown plumage mottled and streaked buff and dark brown. White eye-ring contrasts with dark face. Both sexes similar; females show reduced white eye ring. Iridescent speculum. Critically endangered; only on …
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
Laysan Duck
A tiny brown dabbling duck with distinctive white around the eye and green speculum. The most range-restricted waterfowl in the world; endemic to Laysan Island in the Hawaiian archipelago. Critically Endangered; brought back from single digits in the early 20th century. Feeds on brine flies.
Brent Goose
A small dark-bodied goose with a black head and neck, small white neck patches, and pale grey belly. Migrates between high-Arctic breeding grounds and temperate coastal wintering areas. Feeds on eel-grass and saltmarsh vegetation in winter. Three subspecies differ in belly coloration.