Spatial positioning in the selfish herd
Spatial positioning in the selfish herd
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DOI：
10.1093/beheco/arq157
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发表时间：
2011
影响因子：
2.4
通讯作者：
L. Morrell;G. Ruxton;R. James
中科院分区：
文献类型：
--
作者：
L. Morrell;G. Ruxton;R. James
分组的抗捕食者的好处是相对较好的理解，然而，捕食风险往往不同的个人占据不同的位置在一个组。自私羊群假说描述了个体如何通过移动到群体中的特定位置来降低被捕食的风险。在现有的理论中，这种运动是通过采用可能的“运动规则”而发生的，这些规则在认知复杂性上是不同的。在这里，我们调查了不同的先前建议的规则在降低一组内的中央和外围个人的风险的有效性。我们证明，初始空间位置对于确定不同降低风险运动规则的成功很重要，因为无论使用何种运动规则，最初位于中心位置的个体在降低相对于其他群体成员的风险方面可能比外围个体更成功。更简单的策略在低密度人群中有效;但在高密度人群中，更复杂的规则更有效。我们还发现，复杂的规则，考虑多个邻居的位置是唯一的规则，成功地允许个人从外围移动到中心的位置或保持中心的位置，从而避免捕食者的攻击，从外面的组。我们的研究结果表明，捕食者的攻击策略应该是至关重要的，在确定猎物逃跑策略在自私的羊群背景下，猎物应该修改他们的行为反应，以应对即将到来的攻击，他们在一个组内的位置。版权所有2010年，牛津大学出版社。
The antipredator benefits of grouping are relatively well understood; however, predation risk often differs for individuals that occupy different positions within a group. The selfish herd hypothesis describes how individuals can reduce risk of predation by moving to specific positions within the group. In existing theory, this movement occurs through the adoption of possible "movement rules" that differ in their cognitive complexity. Here, we investigate the effectiveness of different previously suggested rules in reducing risk for central and peripheral individuals within a group. We demonstrate that initial spatial position is important in determining the success of different risk-reducing movement rules, as initially centrally positioned individuals are likely to be more successful than peripheral ones at reducing their risk relative to other group members, regardless of the movement rules used. Simpler strategies are effective in low-density populations; but at high density, more complex rules are more effective. We also find that complex rules that consider the position of multiple neighbors are the only rules that successfully allow individuals to move from peripheral to central positions or maintain central positions, thus avoiding predators that attack from outside the group. Our results suggest that the attack strategy of a predator should be critically important in determining prey escape strategies in a selfish herd context and that prey should modify their behavioral responses to impending attack in response to their position within a group. Copyright 2010, Oxford University Press.