Hawaiian Duck vs Blue-billed Teal
Anas wyvilliana 比較対象 Spatula hottentota
Side-by-Side Comparison
| 属性 | Hawaiian Duck | Blue-billed Teal |
|---|---|---|
| 学名 | Anas wyvilliana | Spatula hottentota |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Vulnerable | Least Concern |
| 体長 | — | — |
| 翼開長 | 44.0 cm (17.3 in) | 29.4 cm (11.6 in) |
| 体重 | 573.25 g (20.22 oz) | 269.2 g (9.50 oz) |
| 食性 | Fish-diving duck of South American rivers; uses serrated bill to catch fish and aquatic invertebrates; … | Feeds on seeds, aquatic plants, and invertebrates; filter-feeds in shallow water; broadly omnivorous and seasonally … |
| 一腹卵数 | 9-13 | 5-12 |
| Population Trend | — | — |
Habitat Comparison
Hawaiian Duck
Freshwater marshes, rivers, reservoirs, and taro fields on Kauai and other Hawaiian islands. Nests in dense vegetation near water. Threatened by hybridization with domestic or feral Mallards.
Blue-billed Teal
Freshwater lakes, marshes, pans, and flooded grasslands across sub-Saharan Africa from Senegal and Sudan south to the Cape. Nomadic; follows seasonal rains. Common but easily overlooked among reed beds.
Song & Call Comparison
Hawaiian Duck
Female produces a raspy, descending quacking series; male gives a soft, nasal sound. Calls similar to Mallard but higher-pitched; alarm is a rapid-fire quacking rattle.
Blue-billed Teal
Male utters a soft, teal-like peep; female gives a muted quack. Pairs call quietly in dense papyrus; soft contact calls help birds maintain proximity in thick African marsh vegetation.
Geographic Range & Migration
Hawaiian Duck
Ranges across sub-Saharan Africa in open grasslands and wetland edges. Locally nomadic following seasonal rainfall patterns.
Blue-billed Teal
Breeds in Arctic and subarctic Eurasia; winters at sea in the North Atlantic and from western Europe to eastern Africa.
保全状況
Hawaiian Duck
Blue-billed Teal
How to Tell Them Apart
Hawaiian Duck
Mottled brown plumage; males may show slight green gloss on head but reduced compared to Mallard. Iridescent blue-purple speculum with white borders. Orange bill. Females similar to males; pale buff …
Blue-billed Teal
Small; males have pale blue-gray bill contrasting with brown-gray body. Head finely spotted; underparts barred brown and white. Males show powder-blue forewing in flight. Females browner. African marsh species.
About These Birds
Hawaiian Duck
ハワイガモはハワイ諸島固有の絶滅危惧種のカモです。マガモに近縁で、雄は緑色の頭部を持ちますが、より地味な外見をしています。湿地や川、池などに生息し、水生植物や無脊椎動物を食べます。外来捕食者や生息地の喪失が主な脅威となっています。
Blue-billed Teal
A small dark teal with blue-grey bill and legs, brown-streaked plumage, and fine pale spotting on the flanks. The most widespread teal in sub-Saharan Africa. Found on freshwater lakes and marshes. Highly nomadic; follows seasonal rainfall. Swims low in the water like a pochard.