Relict Gull
Ichthyaetus relictus
This small black-headed gull breeds on scattered saline lakes throughout central and northern Asia, as far east as Mongolia and northeastern China. However, it is seldom seen on its breeding grounds due to their remoteness. It winters in estuaries, beaches, and mudflats, where adults shed their handsome dark hoods for smudgy “earmuffs.” First winter birds are similar, but have light brown speckling on the wings (solid gray in adults, save for black-and-white tips). Stubbier-billed than Black-headed Gull and generally paler-headed than Saunders's Gull.
识别特征
The gull is 44 to 45 cm long with a stocky, thick body. Non-breeding adults feature uniformly dark-smudged ear-coverts and hind crown, white-tipped wings, prominent, isolated black subterminal markings on outer primaries, and no white leading edge to outer wing. Breeding birds have black hoods (including napes) with grey-brown foreheads, and broad, white, half-moon colouring behind, below, and above their eyes. Their legs are orange and their bills scarlet. The name comes from its status as a relict species.
分类信息
- 学名
- Ichthyaetus relictus
- 命名信息
- (Lönnberg, 1931)
- 目
- Charadriiformes
- 科
- Laridae
- 属
- Ichthyaetus
分布与栖息地
The gull breeds in several locations in Mongolia (e.g., Galuut Lake, Khukh Lake, and Chukh Lake), two in Kazakhstan, one in Russia, and one in China (Lake Hongjiannao). Small numbers appear to migrate to South Korea during the nonbreeding period. There is additional evidence that larger numbers may migrate to eastern China as well, but this is not verified.<p>The gulls breed starting in early June and going through early August in colonies on islands in saltwater lakes. These sites are fragile. Nesting does not occur when lakes dry up or when water levels are too high. When islands become too small or overgrown with vegetation or so large that they join at the shore, the birds do not nest either. During non-breeding periods, the birds can be found on estuarine mud and sandflats.
- 繁殖区
- PAL : lakes of ne Kazakhstan, Mongolia, Inner Mongolia and Shaanxi (nc China) and Transbaikalia (se Russia)
- 非繁殖区
- rare to coasts of Korean Pen., Bohai Bay, Yellow Sea and East China Sea
- 迁徙
- Complete migrants
保护状况
The population is estimated to be at 10,000 or fewer, with numbers dropping. It is classified as "vulnerable" on the IUCN Red List. Its greatest threats are changes of water level in the breeding lakes, predation from other gulls, hailstorms and flooding. Human disturbance has increased their vulnerability to all these factors, resulting in further risks for the adult gulls and increased mortality for chicks and eggs. They are also experiencing trouble migrating to breeding grounds due to the lack of useable stopover locations. In order to combat this, nature reserves in Mongolia, Kazakhstan, and Russia have been established, for example in the Mongol Daguur region.
- 种群趋势
- declining
照片
分布
其他鸟类
Brown-capped Redstart
Myioborus brunniceps
Attractive warbler of montane forest in Bolivia and northwestern Argentina. The broken white eye-ring helps distinguish it from other redstarts in Bolivia, and it is the only redstart found in Argentina. Also note the yellow underparts, rusty crown, and white underside of the tail. Feeds actively at low to middle levels of the forest and sometimes joins mixed-species flocks. Song is a high-pitched, ascending trill.
Papuan King-Parrot
Alisterus chloropterus
A brightly-colored, long-tailed parrot of forest and clearings from the foothills to the mid-mountains. Males have a red head and underparts, blue rump and back of the neck, dark wings and a pale green shoulder bar. Females in the east have green head and upperparts with a red belly. In the west they more resemble the male. Similar to Moluccan King-Parrot but where the ranges meet, but Papuan King-Parrot has a pale green shoulder bar. Call, a series of clear, high, piping notes given at slightly different pitches.
Selva Cacique
Cacicus koepckeae
Rare cacique found very locally in lowland forest in southeastern Peru and extreme SW Brazil, especially near forest-fringed lakes and rivers. Note yellow rump and pale blue eye, which separate it from Solitary Black Cacique. Told from Yellow-rumped Cacique by the yellow being limited to the rump in Selva. No overlap with the closely related Ecuadorian Cacique. It has a varied vocal repertoire, with whistles, metallic squeaks, and various buzzing notes, among other calls.
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。