Blue Duck vs African Pygmy-goose
Hymenolaimus malacorhynchos compared with Nettapus auritus
Side-by-Side Comparison
| Attribute | Blue Duck | African Pygmy-goose |
|---|---|---|
| Scientific Name | Hymenolaimus malacorhynchos | Nettapus auritus |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Endangered | Least Concern |
| Length | — | — |
| Wingspan | 45.6 cm (18.0 in) | 29.9 cm (11.8 in) |
| Weight | 861.75 g (30.40 oz) | 272.5 g (9.61 oz) |
| Diet | Eats aquatic invertebrates, seeds, and plant material; dabbles in shallow fresh water; invertebrate diet peaks … | Filter-feeds on invertebrates and seeds; dabbles in shallow ponds; diet more plant-based outside spring breeding … |
| Clutch Size | 5-6 | 6-12 |
| Population Trend | — | — |
Habitat Comparison
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.
African Pygmy-goose
Freshwater lakes, ponds, and rivers with floating water lilies and other aquatic vegetation across sub-Saharan Africa from Senegal to Tanzania. Nests in tree cavities near water. Highly dependent on water lily vegetation.
Song & Call Comparison
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.
African Pygmy-goose
Male produces a soft, wheezy whistle; female gives a quiet, duck-like quack. Pairs exchange rapid twittering notes during courtship on lily-covered African pools.
Geographic Range & Migration
Blue Duck
Breeds on open prairie wetlands of the Great Plains; winters in shallow estuaries and marshes along the Gulf of Mexico.
African Pygmy-goose
Breeds across temperate to sub-Arctic Eurasia; winters in Africa, South Asia, and Southeast Asia.
Conservation Status
Blue Duck
African Pygmy-goose
How to Tell Them Apart
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.
African Pygmy-goose
Tiny. Males have glossy dark green head with orange facial patch and ear spot; chestnut-orange flanks; white underparts; black and green back. Females duller with dark eye-stripe. Small yellow-green bill.
About These Birds
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.
African Pygmy-goose
A tiny jewel-like duck—one of Africa's smallest waterfowl. Males have iridescent green-and-white plumage, an orange bill, and a dark green cap; females are mottled brown. Found on lily-covered lakes in sub-Saharan Africa. Perches on water lily pads and feeds on their seeds and flowers.