Title: An Alignment-Free Explanation for Collective Predator Evasion in Moving Animal Groups Show Chinese title

Title: 无对齐解释用于移动动物群体中的集体捕食者逃避

Abstract: Moving animal groups consist of many distinct individuals but can operate and function as one unit when performing different tasks. Effectively evading unexpected predator attacks is one primary task for many moving groups. The current explanation for predator evasion responses in moving animal groups require the individuals in the groups interact via (velocity) alignment. However, experiments have shown that some animals do not use alignment. This suggests that another explanation for the predator evasion capacity in at least these species is needed. Here we establish that effective collective predator evasion does not require alignment, it can be induced via attraction and repulsion alone. We also show that speed differences between individuals that have directly observed the predator and those that have not influence evasion success and the speed of the collective evasion process, but are not required to induce the phenomenon. Our work here adds collective predator evasion to a number of phenomena previously thought to require alignment interactions that have recently been shown to emerge from attraction and repulsion alone. Based on our findings we suggest experiments and make predictions that may lead to a deeper understanding of not only collective predator evasion, but also collective motion in general. Show Chinese abstract

Abstract: 移动的动物群体由许多不同的个体组成，但在执行不同任务时可以作为一个单位运作。 有效躲避意外的捕食者攻击是许多移动群体的主要任务之一。 目前对移动动物群体中捕食者逃避反应的解释认为，群体中的个体通过（速度）对齐进行交互。 然而，实验表明，一些动物并不使用对齐。 这表明，至少在这些物种中，需要另一种对捕食者逃避能力的解释。 在这里，我们证明有效的集体捕食者逃避并不需要对齐，仅通过吸引力和排斥力就可以引发。 我们还表明，直接观察到捕食者的个体与未观察到的个体之间的速度差异会影响逃避成功率和集体逃避过程的速度，但并不是引发该现象所必需的。 我们的工作将集体捕食者逃避加入到一些以前被认为需要对齐交互的现象中，这些现象最近已被证明仅从吸引力和排斥力中就能产生。 基于我们的发现，我们建议进行实验并提出预测，这可能有助于更深入地理解不仅包括集体捕食者逃避，还包括一般集体运动的现象。