Tongan Megapode
Megapodius pritchardii
A plump, mostly ground-dwelling bird with long yellowish legs and a dark gray body with slightly browner wash on the wings and back. Head mostly dark gray, with bright orange beak and whitish crest. Good views may show blood-red bare skin around the eye and throat. Found in mature woodland with open understory. Nests on crater lake islands. Resident, with no record of vagrancy. Very vocal, most frequently heard in groups giving chorus of loud piping whistles and shrill cries. Calls are usually a staccato one-note whistle. Unmistakable, as it is the only scrubfowl in its range.
分类信息
- 学名
- Megapodius pritchardii
- 命名信息
- Gray, GR, 1864
- 目
- Galliformes
- 科
- Megapodiidae
- 属
- Megapodius
分布与栖息地
The Tongan megapode is the only remaining species of megapode in Tonga out of the four or five species that were present on the islands in prehuman times (as shown through the fossil record), and indeed the only species of megapode that survives in Polynesia. Similar extinctions occurred in Fiji and New Caledonia, which apparently had three species in prehistory. The species itself once had a more widespread distribution, occurring across most of Tonga, Samoa and Niue. The cause of all these extinctions and declines was the arrival of humans on the islands, and the associated predation on adults and particularly eggs, as well as predation by introduced species.<p>On Niuafo'ou the small human population and remoteness of its habitat probably saved the species. The only megapode to survive human arrival in Western Polynesia, "the megapode nesting grounds were carefully controlled by the ruling chief, thus assuring the continued survival of this population."<p>Its natural habitat is tropical moist lowland forests. On Niuafo'ou it is most common on the central caldera. The Tongan megapode, like all megapodes, does not incubate its eggs by sitting on them; instead the species buries them in warm volcanic sands and soil and allows them to develop. On islands in former parts of its range without volcanoes it presumably created mounds of rotting vegetation and laid the eggs there. The young birds are capable of flying immediately after hatching.
- 迁徙
- Resident species
保护状况
The Tongan megapode is principally threatened by the same factors that caused its decline in the rest of Polynesia. Its eggs are still harvested by local people in spite of theoretical government protection, and some hunting still occurs. The species is apparently afforded some protection by the difficulty in reaching its habitat. Because of the vulnerability of the single population an attempt was made to translocate eggs of this species to new islands, Late and Fonualei. The translocation was successful on Fonualei and an estimated 350–500 birds now breed there, but surveys of Late subsequently found that the translocation there had failed.
- 种群趋势
- rising
照片
分布
其他鸟类
Western Bonelli's Warbler
Phylloscopus bonelli
Small, sleek warbler; white belly contrasts with olive and green upperparts. Very difficult to separate from Eastern Bonelli’s of Eastern Europe. Best character is the call, a two-parted whistle "hu-eef" instead of the sharp “tzip” of Eastern Bonelli’s. Song, a short trilled phrase, is also quite similar to Eastern Bonelli’s. Compare with other leaf warblers; note present species’ plain face, olive-green wing panel (but no bright wing bars), and bright white underparts. Breeds in deciduous forests with oaks and beech, as well as in mixed forest with pines. Non-breeding habitat includes open scrub and open woodlands.
Azure-shouldered Tanager
Thraupis cyanoptera
Large tanager with a strong bill. Pale blue overall with deep-blue patches on the wings. Similar to Sayaca Tanager, but with brighter blue tones to the wings, strong violet blue patches on the wing coverts, and a dark rather than pale area in front of the eye. Found in humid forests, second growth, and forest edges.
Barau's Petrel
Pterodroma baraui
A pale, mid-sized petrel with white underparts, dark cap, white forehead, and black margins to the white underwing. In flight, also note the distinctive, dark “M” on the gray upperparts. Easy, buoyant flight in calm weather, often gaining height and gliding down towards the ocean surface. Wheels high and steeply in strong weather.
开始您的观鸟之旅
在户外识别鸟类，并在下一次观察时随手查阅鸟类图鉴。