Disentangling the biotic and abiotic drivers of emergent migratory behavior using individual-based models
Disentangling the biotic and abiotic drivers of emergent migratory behavior using individual-based models
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DOI：
10.1016/j.ecolmodel.2020.109225
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发表时间：
2020-09-15
影响因子：
3.1
通讯作者：
Hazen, Elliott L.
中科院分区：
文献类型：
--
作者：
Dodson, Stephanie;Abrahms, Briana;Hazen, Elliott L.
了解个体移动、迁移和分布的驱动因素对于深入了解物种如何应对不断变化的环境条件至关重要。非生物因素和生物因素都被认为会影响迁徙行为，但它们的相对作用很难理清。对于迁徙的海洋捕食者，温度和猎物的可获得性已被证明是空间使用的重要预测因素，尽管由于缺乏动态猎物场的数据，研究人员往往依赖于物理代理。我们产生了空间上明确的个人为基础的运动模型，以评估非生物（海表温度; SST）和生物（猎物可用性）的驱动蓝鲸（Balaenoptera musculus）的运动决策和迁移行为在北太平洋东部的因素的相对作用。利用低营养生态系统模型与区域海洋环流模型相结合的输出，我们参数化蓝鲸运动模型，明确纳入猎物领域除了物理代理。一个模型使用SST和猎物数据再现蓝鲸觅食行为，包括现实的纬度迁移的时间。SST和猎物只有人口模型表现出重要的独立影响，每个变量。特别是，SST仅模型显示，温暖的温度限制磷虾觅食的机会，但未能推动季节性觅食模式，而猎物仅模型揭示了更现实的季节性和年际差异觅食行为。我们基于个体的迁移模型有助于阐明迁移的机制，并展示了精细规模的个体决策如何导致人口水平上的紧急迁移行为。此外，确定物理环境和猎物的可获得性对受威胁物种的运动决策的相对影响，对于了解它们如何应对不断变化的海洋条件至关重要。
Understanding the drivers of movement, migration and distribution of individuals is important for insight into how species will respond to changing environmental conditions. Both abiotic and biotic factors are thought to influence migratory behavior, but their relative roles are difficult to disentangle. For migratory marine predators, both temperature and prey availability have been shown to be significant predictors of space use, though often researchers rely on physical proxies due to the lack of data on dynamic prey fields. We generated spatially explicit individual-based movement models to evaluate the relative roles of abiotic (sea surface temperature; SST) and biotic (prey availability) factors in driving blue whale (Balaenoptera musculus) movement decisions and migratory behavior in the eastern North Pacific. Using output from a lower trophic ecosystem model coupled with a regional ocean circulation model, we parameterized a blue whale movement model that explicitly incorporates prey fields in addition to physical proxies. A model using both SST and prey data reproduced blue whale foraging behavior including realistic timing of latitudinal migrations. SST-and prey-only population models demonstrated important independent effects of each variable. In particular, the SST-only model revealed that warm temperatures limited krill foraging opportunities but failed to drive seasonal foraging patterns, whereas the prey-only model revealed more realistic seasonal and interannual differences in foraging behavior. Our individual-based movement model helps elucidate the mechanisms underlying migration and demonstrates how fine-scale individual decision-making can lead to emergent migratory behavior at the population level. Moreover, determining the relative effects of the physical environment and prey availability on the movement decisions of threatened species is critical to understand how they may respond to changing ocean conditions.