Emperor Goose vs Black-headed Duck
Anser canagicus в сравнении с Heteronetta atricapilla
Side-by-Side Comparison
| Характеристика | Emperor Goose | Black-headed Duck |
|---|---|---|
| Научное название | Anser canagicus | Heteronetta atricapilla |
| Отряд | Anseriformes | Anseriformes |
| Семейство | Anatidae | Anatidae |
| Охранный статус | Least Concern | Least Concern |
| Длина | — | — |
| Размах крыльев | 74,8 cm (29.4 in) | 34,7 cm (13.7 in) |
| Масса | 2300,45 g (81.15 oz) | 528,5 g (18.64 oz) |
| Питание | Grazes aquatic plants and terrestrial grasses; upends in shallow water; winter diet shifts toward grain … | Parasitic; adults may feed on aquatic plants, seeds, and invertebrates in South American marshes. Diet … |
| Размер кладки | 1-8 | 2 |
| Population Trend | — | — |
Habitat Comparison
Emperor Goose
Breeds on coastal tundra near the Bering Sea in Alaska and Chukotka. Winters on rocky coastal shorelines, kelp beds, and intertidal flats along the Aleutian Islands and Alaska Peninsula.
Song & Call Comparison
Emperor Goose
A low, nasal 'clag-clag' call. Less vocal than other Anser geese. Gives contact calls in flocks during Arctic breeding and Pacific coast wintering. Somewhat quiet.
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
Emperor Goose
Breeds in the eastern Arctic of Canada; winters along the Atlantic coast from Newfoundland to Florida and occasionally to Texas.
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.
Охранный статус
Emperor Goose
Black-headed Duck
How to Tell Them Apart
Emperor Goose
Body plumage blue-gray with black and white feather scalloping. White head and hindneck contrasting with dark throat. Orange-yellow legs. Bill pink-orange. Tail white. Adults striking; sexes similar.
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
Emperor Goose
A stocky silvery-grey goose with a white head stained orange-yellow from iron-rich water, black-and-white scaly body, and orange-yellow legs. Breeds on Alaska's Yukon-Kuskokwim delta; winters along the Aleutian Islands coastline. Strongly tied to coastal habitats year-round.
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.