Data from: Deceived by stripes: conspicuous patterning on vital anterior body parts can redirect predatory strikes to expendable posterior organs

Conspicuous colouration, which presumably makes prey more visible to predators, has intrigued researchers for long. Contrastingly coloured, conspicuous striped patterns are common among lizards and other animals, but their function is unknown. We propose and test a novel hypothesis, the 'redirection hypothesis', wherein longitudinal striped patterns, such as those found on the anterior body parts of most lacertilians, redirect attacks away from themselves during motion towards less vulnerable posterior parts, for e.g. the autotomous tail. In experiments employing human 'predators’ attacking virtual prey on a touchscreen, we show that longitudinal striped patterns on the anterior half of prey decreased attacks to the anterior, and increased attacks to the posterior. The position of stripes mattered – they worked best when they were at the anterior. By employing an adaptive psychophysical procedure, we show that prey with striped patterning are perceived to move slower, offering a mechanistic explanation for the redirective effect. In summary, our results suggest that the presence of stripes on the body (i.e. head and trunk) of lizards in combination with caudal autotomy can work as an effective antipredator strategy during motion.

醒目体色（conspicuous colouration）本会使猎物更易被捕食者察觉，长期以来一直令研究者们深感着迷。对比色构成的醒目条纹图案在蜥蜴及其他动物类群中颇为常见，但其具体功能至今尚未明确。我们提出并验证了一项全新假说——转向假说（redirection hypothesis），该假说提出：多数蜥蜴亚目（lacertilians）躯体前部所具有的纵向条纹图案，可在猎物移动过程中，将捕食者的攻击目标从自身转移至防御性更强的后部躯体，例如可自割的尾部（autotomous tail）。在以人类作为“捕食者”、在触摸屏上攻击虚拟猎物的行为实验中，我们发现，猎物前半身的纵向条纹图案会减少针对前部的攻击频次，同时提升针对后部的攻击占比。条纹的位置对效果影响显著——当其位于躯体前部时，该策略的效果最佳。通过采用适应性心理物理学实验范式，我们进一步发现，带有条纹图案的猎物会被观察者感知为移动速度更慢，这为转向效应提供了机制层面的合理解释。综上，我们的研究结果表明，蜥蜴躯体（即头部与躯干）上的条纹图案与尾部自割（caudal autotomy）相结合，可在移动过程中成为一种高效的反捕食策略。