Scaling laws of marine predator search behaviour
Scaling laws of marine predator search behaviour
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DOI：
10.1038/nature06518
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发表时间：
2008-02-28
期刊：
影响因子：
64.8
通讯作者：
Metcalfe, Julian D.
中科院分区：
文献类型：
--
作者：
Sims, David W.;Southall, Emily J.;Metcalfe, Julian D.
许多自由放养的捕食者在对目前资源分布和可用性知之甚少的情况下不得不做出觅食决定（1）。最佳的搜索策略，他们应该使用最大限度地提高遇到率与猎物在异质的自然环境中仍然是一个很大程度上未解决的问题，在生态学（1-3）。利维行走（4）是一种特殊的随机行走，产生分形运动轨迹，可以代表搜索复杂景观的最佳解决方案（5）。然而，这种假定的策略对自然猎物分布的适应性意义尚未得到验证（6，7）。在这里，我们分析了从动物附着的电子标签记录的超过100万个运动位移，以表明不同的海洋捕食者-鲨鱼，硬骨鱼，海龟和企鹅-表现出接近理论最优值的利维行走行为（2）。猎物密度分布也显示出类似Levy的分形图案，表明捕食者对猎物分布的反应运动.模拟结果表明，与纯粹随机的景观相比，捕食者在类似自然的猎物场中采用Levy型觅食时有更高的遭遇率。这与观测到的搜索模式适应于观测到的景观统计模式的假设是一致的。这也许可以解释为什么利维式行为似乎在从微生物（8）到人类（9）的各种生物体（3）中广泛存在，作为一种“规则”，它是为了应对不均匀的资源分布而进化的。
Many free- ranging predators have to make foraging decisions with little, if any, knowledge of present resource distribution and availability(1). The optimal search strategy they should use to maximize encounter rates with prey in heterogeneous natural environments remains a largely unresolved issue in ecology(1-3). Levy walks(4) are specialized random walks giving rise to fractal movement trajectories that may represent an optimal solution for searching complex landscapes(5). However, the adaptive significance of this putative strategy in response to natural prey distributions remains untested(6,7). Here we analyse over a million movement displacements recorded from animal- attached electronic tags to show that diverse marine predators - sharks, bony fishes, sea turtles and penguins - exhibit Levy- walk- like behaviour close to a theoretical optimum(2). Prey density distributions also display Levy- like fractal patterns, suggesting response movements by predators to prey distributions. Simulations show that predators have higher encounter rates when adopting Levy- type foraging in natural- like prey fields compared with purely random landscapes. This is consistent with the hypothesis that observed search patterns are adapted to observed statistical patterns of the landscape. This may explain why Levy- like behaviour seems to be widespread among diverse organisms(3), from microbes(8) to humans(9), as a `rule' that evolved in response to patchy resource distributions.