Radjah Shelduck
Radjah radjah
Large black and white duck with obvious pale eye, pale bill, and chunky pale-colored legs. Note narrow dark breast-band. Typically found on and around wetlands, rivers and sewage ponds, including mangroves.
识别特征
Both the male and female of the species are mostly white, with dark wing-tips and a distinctive "collar" of dark feathers. When viewed from above, during flight or with wings outstretched, green bands are visible on the tops of their wings. To communicate, the female utters a harsh rattle while the male emits a breathy, "sore-throat" whistle.
分类信息
The specific name radjah is from the Moluccan name Radja for the radjahshelduck on the island of Buru in Indonesia.<p>Formerly placed in the genus Tadorna, it differs markedly from other members in external morphology and mtDNA cytochrome b sequence data, suggesting its status should be reinvestigated. Current classification places it in its own monotypic genus Radjah.
- 学名
- Radjah radjah
- 命名信息
- (Garnot & Lesson, RP, 1828)
- 目
- Anseriformes
- 科
- Anatidae
- 属
- Radjah
分布与栖息地
The radjah shelduck inhabits the mangrove forests and coastline of New Guinea (West Papua and Papua New Guinea) and Australia, and some of the Moluccas in eastern Indonesia. In Australia, its primary range is coastal, tropical northern Australia, extending as far south as central Queensland, west through the upper regions of the Northern Territory (including Kakadu National Park) to the Kimberley in Western Australia. The radjah shelduck is listed as a protected bird in all the states of Australia, and penalties are enforced for harming or disturbing them.<p>The species prefers the salty waters of mangrove flats and paperbark tree swamps, but will visit all manner of brackish and freshwater swamps, lagoons, lakes, estuaries, river deltas, and billabongs further inland during the wet season.
- 迁徙
- Resident species
行为
The radjah shelduck forms long-term, bonded pairs, and they are usually encountered in lone pairs or small flocks. During the rainy season, the males commonly become very irritable, and have been observed attacking their mates.<p>The ducks' preferred diet consists mainly of mollusks, aquatic or other insects, worms, aquatic weeds, sedge materials and algae. Pairs start searching for nesting sites during the months of January and February. They nest close to their primary food source, often in the hollow limbs of dead or dehydrated trees, which makes habitat destruction a particular issue.<p>The radjah shelduck does not use nesting materials apart from some self-supplied down feathers. Egg-laying is usually completed by May or June, but depends on the extent of the wet season. The clutches range from 6 to 12 eggs. Incubation time is about 30 days.<p>
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Bronze-tailed Starling
Lamprotornis chalcurus
A beautiful, glossy green-and-purple starling. There is a stripe through the eye that sometimes looks black and sometimes deep purple. The eye is reddish-orange. Juveniles are dull and blackish. Found in a wide variety of savanna habitats, from moist broadleaf woodland to dry thorn savanna. Also found in villages, towns, and cultivated areas. Very similar to Lesser and Greater Blue-eared Starlings, but separated by the purple rather than greenish tail and the darker reddish eye. The vocalizations include rising whistles, nasal whines, and long series of chattering notes.
Rufous Treepie
Dendrocitta vagabunda
A long- and stiff-tailed bird with primarily rusty-brown upperparts and dull orangish underparts. The head, mantle, and neck region are a dull, sooty black. The long graduated tail is pale gray with a wide black terminal band. Note the conspicuous silvery-gray, white, and black patterns on the wings. The blackish-gray bill is stout with a hooked tip. Found in a wide range of habitats from woodlands to scrubby patches, singly or in pairs feeding in the treetops. The call is a loud metallic “krowwiiii kroo.”
Lowland Akalat
Sheppardia cyornithopsis
A small shy akalat found in the lower levels of tall forests, often in dark shady areas near water. Note the reddish-brown back and wings, the gray face, and the bright red-orange chest contrasting with a white belly. Almost always found in lowland forest, but a few local populations are found higher up in the foothills. Within its range, most likely to be confused with Forest Robin, but note Lowland Akalat’s plain gray face and distinctive vocalizations. Song is a series of clear, melancholy whistles given with slight pauses in between, “wheeer, gowheer,” as well as faster, more resonant and metallic series of whistles.
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