Animal search strategies: A quantitative. random-walk analysis
Animal search strategies: A quantitative. random-walk analysis
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DOI：
10.1890/04-1806
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发表时间：
2005-11-01
期刊：
影响因子：
4.8
通讯作者：
Catalan, J
中科院分区：
文献类型：
--
作者：
Bartumeus, F;Da Luz, MGE;Catalan, J
空间生态学的最新进展改善了我们对大规模动物运动作用的理解。但是，一个未解决的问题涉及许多动物搜索位移及其可能的适应价值所涉及的固有随机性。当动物没有有关目标（即资源贴片，伴侣等）的信息时，不同的随机搜索策略可能会提供不同的机会来找到它们。假设随机步行模型是了解动物如何面对这种环境不确定性的必要工具，我们分析了通常用于适合动物运动数据的两个随机步行模型之间的统计差异，征费步行和相关的随机步行，我们量化了它们在随机搜索上下文中的效率（即，与总位移有关的目标数量）。相关的随机步行特性（即比例尺相关性）可以解释为局部扫描机制的副产品。相反，Levy Walks具有基本属性（即超扩散性和规模不变性），可以在随机搜索方案中提高效率。与动物如何通过在随机搜索中突然的重新定位对动作打断运动的特定生物学机制将足以维持征税行走特性。此外，我们研究了一个新的模型（征收调制的相关随机步行），该模型结合了相关和征收步行的特性。该模型表明，征税步行属性对于在步行中提供短程相关性的任何行为机制都是可靠的。我们建议有些动物可能已经进化了。表演征费的能力作为适应性策略，以面对搜索不确定性。
Recent advances in spatial ecology have improved our understanding of the role of large-scale animal movements. However, an unsolved problem concerns the inherent stochasticity involved in many animal search displacements and its possible adaptive value. When animals have no information about where targets (i.e., resource patches, mates, etc.) are located, different random search strategies may provide different chances to find them. Assuming random-walk models as a necessary tool to understand how animals face such environmental uncertainty, we analyze the statistical differences between two random-walk models commonly used to fit animal movement data, the Levy walks and the correlated random walks, and we quantify their efficiencies (i.e., the number of targets found in relation to total displacement) within a random search context. Correlated random-walk properties (i.e., scale-finite correlations) may be interpreted as the by-product of locally scanning mechanisms. Levy walks, instead, have fundamental properties (i.e., super-diffusivity and scale invariance) that allow a higher efficiency in random search scenarios. Specific biological mechanisms related to how animals punctuate their movement with sudden reorientations in a random search would be sufficient to, sustain Levy walk properties. Furthermore, we investigate a new model (the Levy-modulated correlated random walk) that combines the properties of correlated and Levy walks. This model shows that Levy walk properties are robust to any behavioral mechanism providing short-range correlations in the walk. We propose that some animals may have evolved the. ability of performing Levy walks as adaptive strategies in order to face search uncertainties.