Estimating updraft velocity components over large spatial scales: contrasting migration strategies of golden eagles and turkey vultures
Estimating updraft velocity components over large spatial scales: contrasting migration strategies of golden eagles and turkey vultures
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DOI：
10.1111/j.1461-0248.2011.01713.x
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发表时间：
2012-02-01
期刊：
影响因子：
8.8
通讯作者：
Tremblay, Junior A.
中科院分区：
文献类型：
--
作者：
Bohrer, Gil;Brandes, David;Tremblay, Junior A.
飞翔的鸟类在全球范围内大量迁徙。这些迁徙是复杂和动态的现象，受到气象条件的强烈影响，当鸟类穿越地形时，气象条件会产生热隆起和地形抬升。在这里，我们报告了如何利用公开可用的大陆尺度的数字天气和地形数据集来估计热隆起和地形隆起的强度的方法。我们应用这些方法来对比两个在形态上相似但行为上不同的物种的飞行策略：金鹰、金雕和土耳其秃鹰，它们在北美东部的秋季迁徙过程中，使用GPS标签进行跟踪。我们发现，土耳其秃鹫在迁徙过程中几乎只使用热升力，而金鹰在迁徙过程中主要使用地形升力。以前还没有显示出迁徙轨迹受到特定物种专门化到特定隆升模式的影响。本文介绍的估计抬升分量和检验天气用途差异的方法可用于研究任何高涨物种的运动。
Soaring birds migrate in massive numbers worldwide. These migrations are complex and dynamic phenomena, strongly influenced by meteorological conditions that produce thermal and orographic uplift as the birds traverse the landscape. Herein we report on how methods were developed to estimate the strength of thermal and orographic uplift using publicly available digital weather and topography datasets at continental scale. We apply these methods to contrast flight strategies of two morphologically similar but behaviourally different species: golden eagle, Aquila chrysaetos, and turkey vulture, Cathartes aura, during autumn migration across eastern North America tracked using GPS tags. We show that turkey vultures nearly exclusively used thermal lift, whereas golden eagles primarily use orographic lift during migration. It has not been shown previously that migration tracks are affected by species-specific specialisation to a particular uplift mode. The methods introduced herein to estimate uplift components and test for differences in weather use can be applied to study movement of any soaring species.