Negotiating an ecological barrier: crossing the Sahara in relation to winds by common swifts
Negotiating an ecological barrier: crossing the Sahara in relation to winds by common swifts
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DOI：
10.1098/rstb.2015.0393
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发表时间：
2016-09-26
影响因子：
6.3
通讯作者：
Hedenstrom, Anders
中科院分区：
文献类型：
--
作者：
Akesson, Susanne;Bianco, Giuseppe;Hedenstrom, Anders
撒哈拉沙漠是地球上最大的陆地屏障之一，每年有数十亿鸟类迁徙两次。在这里，我们调查如何常见的雨燕在瑞典和撒哈拉以南非洲的越冬地区之间的繁殖地迁移执行沙漠穿越的路线选择，风，时间和速度的迁移通过分析72 geolocator轨道记录迁移。雨燕在秋天以宽阔的战线穿越西撒哈拉，而在春天，它们似乎使用三条穿越撒哈拉的替代路线，一条是穿越阿拉伯半岛的西部、中部和东部路线，大多数鸟类使用西部路线。与春季相比，雨燕的迁徙和旅行速度较慢，并且在秋季绕行更长，停留更多。春季，在西非停留的时间与大多数有利的风相吻合，但鸟类仍然留在该地区，这表明燃料。在春季，西部路线比中部路线提供了更多的顺风帮助，但在秋季没有。最后的解释是西方路线的演变可能是相匹配的丰富的觅食条件（成群的昆虫）和有利的风使快速春季迁移相结合。这篇文章是主题问题的一部分“在移动的媒介中移动：飞行的新视角”。
The Sahara Desert is one of the largest land-based barriers on the Earth, crossed twice each year by billions of birds on migration. Here we investigate how common swifts migrating between breeding sites in Sweden and wintering areas in sub-Saharan Africa perform the desert crossing with respect to route choice, winds, timing and speed of migration by analysing 72 geolocator tracks recording migration. The swifts cross western Sahara on a broad front in autumn, while in spring they seem to use three alternative routes across the Sahara, a western, a central and an eastern route across the Arabian Peninsula, with most birds using the western route. The swifts show slower migration and travel speeds, and make longer detours with more stops in autumn compared with spring. In spring, the stopover period in West Africa coincided with mostly favourable winds, but birds remained in the area, suggesting fuelling. The western route provided more tailwind assistance compared with the central route for our tracked swifts in spring, but not in autumn. The ultimate explanation for the evolution of a preferred western route is presumably a combination of matching rich foraging conditions (swarming insects) and favourable winds enabling fast spring migration.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.