School of Biology , Indian Institute of Science Education and Research Thiruvananthapuram , CET campus, Trivandrum 695016 , India.
R Soc Open Sci. 2016 Jun 8;3(6):160057. doi: 10.1098/rsos.160057. eCollection 2016 Jun.
Conspicuous coloration, 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 not well known. 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 example, 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 anti-predator strategy during motion.
明显的颜色，据推测会使猎物更容易被捕食者发现，长期以来一直引起研究人员的兴趣。对比鲜明的、显眼的条纹图案在蜥蜴和其他动物中很常见，但它们的功能并不为人所知。我们提出并测试了一个新的假设，即“ redirectedirection hypothesis”，其中纵向条纹图案，如大多数蜥蜴类动物前体部分的条纹，在运动时将攻击从自身转移到较不易受攻击的后体部分，例如自切的尾巴。在实验中，我们使用人类“捕食者”在触摸屏上攻击虚拟猎物，结果表明，猎物前半部分的纵向条纹图案减少了对前部的攻击，增加了对后部的攻击。条纹的位置很重要——当它们在前部时效果最好。通过采用自适应心理物理程序，我们表明具有条纹图案的猎物被感知为移动速度较慢，为这种 redirectedirection 效应提供了一种机械解释。总之，我们的结果表明，蜥蜴身体（即头部和躯干）上的条纹的存在与尾部自切相结合，可以在运动过程中成为一种有效的抗捕食者策略。
