Mallard vs Steller's Eider
Anas platyrhynchos compared with Polysticta stelleri
Side-by-Side Comparison
| Attribute | Mallard | Steller's Eider |
|---|---|---|
| Scientific Name | Anas platyrhynchos | Polysticta stelleri |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Vulnerable |
| Length | 58.0 cm (22.8 in) | — |
| Wingspan | 90.0 cm (35.4 in) | 40.7 cm (16.0 in) |
| Weight | 1100.0 g (38.80 oz) | 815.75 g (28.77 oz) |
| Diet | Omnivorous — aquatic plants, seeds, insects, crustaceans, and mollusks. Feeds by dabbling, upending, and grazing … | Eats molluscs, crustaceans, and aquatic invertebrates; dives in shallow coastal and estuarine habitats; diet invertebrate-dominated. |
| Clutch Size | 4-18 | 3-10 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Mallard
Nearly any wetland habitat including lakes, rivers, ponds, marshes, estuaries, and urban park ponds.
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
Mallard
Female gives the classic 'quack-quack-quack', descending in pitch. Male utters soft nasal 'raeb-raeb'. Both give a high 'gag-gag-gag' when alarmed or taking 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
Mallard
Native across the Northern Hemisphere in North America, Europe, and Asia. Introduced to Australia and New Zealand.
Steller's Eider
Breeds in boreal Canada and Alaska; winters along Pacific and Atlantic coasts and on large interior lakes of the US.
Conservation Status
Mallard
Steller's Eider
How to Tell Them Apart
Mallard
Breeding males have an iridescent green head, white neck ring, chestnut breast, and grey body. Females are mottled brown. Both sexes show a blue speculum bordered by white.
Broad, flat bill — yellow-green in males, orange-brown in females
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
Mallard
The mallard is the ancestor of most domestic duck breeds and the most abundant and widespread dabbling duck in the world. Males perform elaborate courtship displays including head-bobbing and whistle-grunt calls. Mallards are highly adaptable, thriving in both wilderness and urban environments.
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.