Department of Animal Ecology, Lund University, Ecology Building, 22362 Lund, Sweden.
Proc Biol Sci. 2011 May 7;278(1710):1339-46. doi: 10.1098/rspb.2010.2106. Epub 2010 Oct 27.
Wind and ocean currents may potentially have important effects on travelling animals, as an animal which does not respond to lateral flow will be drifted from its intended direction of movement. By analysing daily movements of migrating ospreys Pandion haliaetus and marsh harriers Circus aeruginosus, as recorded by satellite telemetry, in relation to global wind data, we showed that these raptors allow on average 47 per cent drift. Furthermore, our analyses revealed significant geographical and temporal variation in the response to crosswinds. During some parts of the migration, the birds drifted and in other parts they compensated or even overcompensated. In some regions, the response of marsh harriers depended on the wind direction. They drifted when the wind came from one side and (over)compensated when the wind came from the opposite side, and this flexible response was different in different geographical regions. These results suggest that migrating raptors modulate their response to crosswinds at different places and times during their travels and show that individual birds use a much more varied repertoire of behavioural responses to wind than hitherto assumed. Our results may also explain why contrasting and variable results have been obtained in previous studies of the effect of wind on bird migration.
风与洋流可能会对洄游动物产生重要影响，因为对于侧风没有反应的动物，其移动方向会发生偏移。我们通过卫星遥测技术，分析了游隼（Pandion haliaetus）和普通鵟（Circus aeruginosus）这两种迁徙猛禽的日常移动与全球风数据之间的关系，结果表明这些猛禽的平均偏移率为 47%。此外，我们的分析还揭示了其对侧风响应的显著地理和时间变化。在迁徙的某些阶段，鸟类会偏移，而在其他阶段，它们会进行补偿，甚至过度补偿。在某些地区，普通鵟对风的响应取决于风向。当风从一侧吹来时，它们会偏移，而当风从另一侧吹来时，它们会过度补偿，这种灵活的响应在不同地理区域有所不同。这些结果表明，迁徙猛禽在迁徙过程中的不同地点和时间会调节其对侧风的响应，并且表明个体鸟类在应对风的行为反应上比以往假设的更加多样化。我们的研究结果还可以解释为什么在之前关于风对鸟类迁徙影响的研究中，得到的结果既相互矛盾又具有多变性。
