Data from: Unpredictable movement as an anti-predator strategy

Prey animals have evolved a wide variety of behaviours to combat the threat of predation, and these have been generally well studied. However, one of the most common and taxonomically widespread antipredator behaviours of all has, remarkably, received almost no experimental attention: so-called ‘protean’ behaviour. This is behaviour which is sufficiently unpredictable to prevent a predator anticipating in detail the future position or actions of its prey. In this study, we used human ‘predators’ participating in 3D virtual reality simulations to test how protean (i.e. unpredictable) variation in prey movement affects participants’ ability to visually target them as they move (a key determinant of successful predation). We found that targeting accuracy was significantly predicted by prey movement path complexity, although, surprisingly, there was little evidence that high levels of unpredictability in the underlying movement rules equated directly to decreased predator performance. Instead, the specific movement rules differed in how they impacted on targeting accuracy, with the efficacy of protean variation in one element depending on the values of the remaining elements. These findings provide important insights into the understudied phenomenon of protean antipredator behaviour, which are directly applicable to predator-prey dynamics within a broad range of taxa.猎物动物已演化出多种多样的行为以应对捕食威胁，这类行为迄今已得到较为充分的研究。然而，在所有已知的反捕食行为中，最为常见且在分类学上分布极广的一类行为却几乎未受到实验关注——即所谓的“多变行为（protean behaviour）”。这类行为具备足够强的不可预测性，可阻止捕食者精准预判猎物的未来位置与行动。本研究借助参与3D虚拟现实模拟实验的人类“捕食者”，探究猎物移动过程中的多变（即不可预测）变化如何影响参与者在猎物移动时对其进行视觉锁定的能力——这是决定捕食成功与否的关键因素。研究发现，猎物移动路径的复杂度可显著预测锁定准确率；但令人意外的是，几乎没有证据表明底层运动规则的高不可预测性会直接降低捕食者的表现。反之，不同的具体运动规则对锁定准确率的影响存在差异，某一要素的多变性效应取决于其余要素的取值。本研究结果为这一长期未得到充分研究的多变反捕食行为现象提供了重要见解，且其结论可直接应用于多个分类群的捕食者-猎物动态研究中。