Eco-Ethology Research Unit, ISPA, Rua Jardim do Tabaco 34, 1149-041 Lisboa, Portugal.
Proc Biol Sci. 2011 Jun 22;278(1713):1786-93. doi: 10.1098/rspb.2010.2114. Epub 2010 Nov 24.
There is growing evidence that migratory species are particularly vulnerable to rapid environmental changes arising from human activity. Species are expected to vary in their capacity to respond to these changes: long-distance migrants and those lacking variability in migratory traits are probably at considerable disadvantage. The few studies that have assessed the degree of plasticity in behaviour of marine animals suggest that fidelity to non-breeding destinations is usually high. In the present study, we evaluated individual flexibility in migration strategy of a highly pelagic seabird, the Cory's shearwater Calonectris diomedea. Geolocation data from 72 different migrations, including 14 birds that were tracked for more than one non-breeding season, showed a remarkable capacity to change winter destinations between years. Although some birds exhibited high site fidelity, others shifted from the South to North Atlantic, from the western to eastern South Atlantic, and from the Atlantic to Indian Ocean. Individuals also showed flexibility in stopover behaviour and migratory schedule. Although their K-selected life-history strategy has the disadvantage that the chances of microevolution are slight if circumstances alter rapidly, these results suggest that Cory's shearwaters may be in a better position than many other long-distance migrants to face the consequences of a changing environment.
越来越多的证据表明，迁徙物种特别容易受到人类活动引起的快速环境变化的影响。预计物种在应对这些变化的能力上会有所不同：长距离迁徙者和那些在迁徙特征上没有可变性的物种可能处于相当大的劣势。少数评估海洋动物行为可塑性程度的研究表明，对非繁殖地的忠诚度通常很高。在本研究中，我们评估了一种高度远洋海鸟——角海雀 Calonectris diomedea 的迁徙策略的个体灵活性。来自 72 次不同迁徙的地理定位数据，包括 14 只跟踪了一个以上非繁殖季节的鸟类，显示出在不同年份间改变冬季目的地的显著能力。尽管有些鸟类表现出高度的栖息地忠诚度，但其他鸟类则从南大西洋转移到北大西洋，从西南大西洋转移到东南大西洋，从大西洋转移到印度洋。个体在中途停留行为和迁徙计划方面也表现出灵活性。尽管它们的 K 选择生活史策略的劣势是，如果环境迅速改变，微进化的机会微乎其微，但这些结果表明，角海雀可能比许多其他长距离迁徙者更有能力应对不断变化的环境的后果。
