American Black Duck vs Blue Duck
Anas rubripes в сравнении с Hymenolaimus malacorhynchos
Side-by-Side Comparison
| Характеристика | American Black Duck | Blue Duck |
|---|---|---|
| Научное название | Anas rubripes | Hymenolaimus malacorhynchos |
| Отряд | Anseriformes | Anseriformes |
| Семейство | Anatidae | Anatidae |
| Охранный статус | Least Concern | Endangered |
| Длина | — | — |
| Размах крыльев | 53,4 cm (21.0 in) | 45,6 cm (18.0 in) |
| Масса | 1211,25 g (42.73 oz) | 861,75 g (30.40 oz) |
| Питание | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Eats aquatic invertebrates, seeds, and plant material; dabbles in shallow fresh water; invertebrate diet peaks … |
| Размер кладки | 1-17 | 5-6 |
| Population Trend | — | — |
Habitat Comparison
American Black Duck
Freshwater and brackish wetlands in eastern North America from Atlantic Canada south along the coast to Georgia. Breeds in northern bogs and wetlands. Winters on coastal marshes, estuaries, and freshwater lakes.
Blue Duck
Fast-flowing clear turbulent mountain rivers and streams in pristine native forest at 300–1,500 m in both main islands of New Zealand. Requires undisturbed riparian habitat with abundant aquatic invertebrates.
Song & Call Comparison
American Black Duck
Female produces a loud, deep quacking series; male gives a low, raspy grunt. Voice is deeper and huskier than a Mallard; pairs call powerfully across northeastern North American wetlands.
Blue Duck
A soft, musical whistle from fast-flowing South Island rivers. Call is a clear 'whio' — giving the bird its Maori name. Also gives a soft, reedy 'squeak'. Endangered; rarely heard.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Blue Duck
Breeds on open prairie wetlands of the Great Plains; winters in shallow estuaries and marshes along the Gulf of Mexico.
Охранный статус
American Black Duck
Blue Duck
How to Tell Them Apart
American Black Duck
Sooty dark brown body; head and neck paler buff with dark streaking. Iridescent purple speculum without white border. Males have yellow-green bill; females olive with orange blotches. Silvery underwings in …
Blue Duck
Distinctive slate-blue-gray plumage; breast spotted with chestnut-brown in both sexes. Pale bill with flexible pink lobes at tip. Chestnut eye. Sexes similar; adapted to fast-flowing mountain streams in New Zealand.
About These Birds
American Black Duck
A large dark brown dabbling duck closely resembling a very dark female Mallard, with purple speculum, yellowish-olive bill in males, and orange legs. Common in eastern North America. Hybridizes freely with Mallard; pure populations declining in the interior.
Blue Duck
A medium-sized blue-grey torrent duck with a pale pink bill tipped with a distinctive flap of skin, and chestnut-spotted breast. Endemic to New Zealand's fast-flowing mountain rivers. One of New Zealand's most endangered endemics. Monogamous with strong site fidelity to individual river territories.