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发帖数: 26222 | 1 在俄国繁殖的鸟可能到旧金山过冬，而阿拉斯加的鸟有可能飞到马来西亚。
靠，神奇啊。
These transcontinental migrants, which traveled primarily in the daytime,
flew far too high to be observed and identified visually. However, evidence
suggests that they are mostly shorebirds—such as Red Phalaropes and Long-
billed Dowitchers—along with some species of tern and skua. By flying east
to the North American mainland before turning south, they reduce the
distance they must fly over inhospitable seas. In fact, the route is similar
to the "great-circle route" that transcontinental airliners follow across
the Arctic.
The study detected far fewer westward-flying birds. Most westbound migrants
flew at lower elevations, migrated at night, and had radar signatures
characteristic of songbirds. They probably were species like the Arctic
Warbler, Bluethroat, and Northern Wheatear—birds that have colonized
Western Alaska from Siberia, but still return to their ancestral Eurasian
wintering grounds.
These avian journeys across the Bering region highlight the connectedness of
the world's migratory birds. Some of the dowitchers wintering in San
Francisco Bay probably breed in northern Russia, and some of the Arctic
Warblers that hatch in Alaska's Denali National Park may fly all the way to
Malaysia. |
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