Snow Goose vs Black-headed Duck
Anser caerulescens so với Heteronetta atricapilla
Side-by-Side Comparison
| Thuộc Tính | Snow Goose | Black-headed Duck |
|---|---|---|
| Tên Khoa Học | Anser caerulescens | Heteronetta atricapilla |
| Bộ | Anseriformes | Anseriformes |
| Họ | Anatidae | Anatidae |
| Tình Trạng Bảo Tồn | Least Concern | Least Concern |
| Chiều Dài | — | — |
| Chiều Dài Sải Cánh | 82,4 cm (32.4 in) | 34,7 cm (13.7 in) |
| Khối Lượng | 2561,0 g (90.34 oz) | 528,5 g (18.64 oz) |
| Chế Độ Ăn | Grazes submerged aquatic vegetation and eelgrass in estuaries; also takes grasses and sedges on coastal … | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … |
| Số Trứng | 2-6 | 2 |
| Population Trend | — | — |
Habitat Comparison
Snow Goose
Breeds on coastal and inland Arctic tundra in Canada, Alaska, and Greenland. Winters on agricultural fields, marshes, and coastal wetlands across the United States and northern Mexico. Forms enormous flocks.
Song & Call Comparison
Snow Goose
A loud, nasal barking 'luk-luk' or 'kow-kow'. Large flocks create enormous noise during Arctic nesting and winter staging. Considered a noisy, conspicuous goose.
Black-headed Duck
Male gives a soft, raspy peeping note; female produces a muted quack. An obligate brood parasite with reduced vocalizations; subdued calls suit its secretive lifestyle among Argentine reeds.
Geographic Range & Migration
Snow Goose
Breeds in eastern North America's boreal forest; winters on the Atlantic coast from New England to South Carolina.
Black-headed Duck
Resident in southern South America from southern Brazil and Bolivia south to Argentina and Chile. Found on lakes and marshes in open lowlands.
Tình Trạng Bảo Tồn
Snow Goose
Black-headed Duck
How to Tell Them Apart
Snow Goose
White morph: pure white plumage with black primaries and pink bill and legs. Blue morph: dark blue-gray body with white head. Both morphs interbreed freely. 'Grinning patch' on bill. Sexes …
Black-headed Duck
Male has distinctive jet-black head and neck, warm chestnut-brown back, and pale buff underparts; blue-grey bill with red base. Female is streaked brown above with pale supercilium and whitish underparts.
About These Birds
Snow Goose
A distinctive goose with two morphs—white with black wingtips, or 'blue morph' with dark body and white head. Large flocks create spectacular migration events. Breeds in the Arctic; winters in the United States and Mexico. Population growth has caused severe overgrazing of Arctic salt marshes.
Black-headed Duck
A small diving duck (~530 g) of South America, family Anatidae, and the sole member of genus Heteronetta. Inhabits freshwater marshes and lakes in Argentina, Bolivia, Brazil, Chile, and Uruguay. Unique among waterfowl as an obligate brood parasite, laying eggs in nests of coots and other waterbirds. Feeds on seeds and aquatic invertebrates. Least Concern.