Black Swan vs Steller's Eider
Cygnus atratus เปรียบเทียบกับ Polysticta stelleri
Side-by-Side Comparison
| คุณสมบัติ | Black Swan | Steller's Eider |
|---|---|---|
| ชื่อวิทยาศาสตร์ | Cygnus atratus | Polysticta stelleri |
| อันดับ | Anseriformes | Anseriformes |
| วงศ์ตระกูล | Anatidae | Anatidae |
| สถานะการอนุรักษ์ | Least Concern | Vulnerable |
| ความยาว | 130.0 cm (51.2 in) | — |
| กว้างปีก | 190.0 cm (74.8 in) | 40.7 cm (16.0 in) |
| น้ำหนัก | 6200.0 g (218.70 oz) | 815.75 g (28.77 oz) |
| อาหาร | Aquatic vegetation and algae, supplemented with grain and pasture grasses. Feeds by upending in shallow … | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal and estuarine habitats; diet invertebrate-dominated. |
| จำนวนไข่ | 4-6 | 3-10 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Black Swan
Lakes, rivers, swamps, and coastal waters across Australia. Also found in ornamental lakes in parks.
Steller's Eider
Breeds on low-lying coastal tundra in Arctic Russia and occasionally Alaska. Winters on shallow rocky sea coasts, kelp beds, and sheltered bays in the Baltic Sea and Pacific coast of Alaska. Listed as Vulnerable.
Song & Call Comparison
Black Swan
Gives a musical bugling 'boo-boo-boo' in flight and softer honking on water. Less vocal than Mute Swan; produces a baying call when alarmed. Wings whistle softly in flight.
Steller's Eider
Male produces a low, soft cooing note; female gives a guttural, grunting purr. Quieter than other eiders; the male's gentle cooing is unlike the louder calls of the Common Eider.
Geographic Range & Migration
Black Swan
Australia, primarily in the southeast and southwest. Introduced populations in New Zealand, Japan, and western Europe.
Steller's Eider
Breeds in boreal Canada and Alaska; winters along Pacific and Atlantic coasts and on large interior lakes of the US.
สถานะการอนุรักษ์
Black Swan
Steller's Eider
How to Tell Them Apart
Black Swan
Almost entirely black with white flight feathers visible in flight. Red bill with a white band near the tip. Dark red to reddish-brown iris.
Bright red bill with a pale tip and prominent white band
Steller's Eider
Males have white head with green nape spot, black eye patch and chin; orange-buff underparts; black back with white wing patches. Females mottled dark brown with blue speculum bordered white. …
About These Birds
Black Swan
The black swan was once considered impossible by Europeans who believed all swans were white, making it a famous philosophical example of inductive reasoning failure. It is the state emblem of Western Australia. Black swans form lifelong pair bonds and both parents share in incubation and care of cygnets.
Steller's Eider
A small sea duck. Males have a white head with green facial markings, black throat patch, chestnut underparts, and white back; females are dark brown. The smallest eider. Breeds in Arctic tundra; winters in Baltic Sea and Alaskan coastal waters. Vulnerable to contaminants and oil spills.