Zlotnik Sara, Darnell Geena M, Bernal Ximena E
Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Republic of Panama.
Anim Cogn. 2018 Sep;21(5):729-733. doi: 10.1007/s10071-018-1199-6. Epub 2018 Jun 19.
Predators everywhere impose strong selection pressures on the morphology and behavior of their prey, but the resulting antipredator adaptations vary greatly among species. Studies of adaptive coloration in prey species have generally focused on cryptic or aposematic prey, with little consideration of color patterns in palatable mobile prey. Complex color patterns have been proposed to decrease the ability of visual predators to capture moving prey (motion dazzle effect). Most support for this hypothesis, however, comes from experiments with human subjects and simulated prey. We tested the motion dazzle effect using, for the first time, natural predators (cane toads, Rhinella marina) and live prey (house crickets, Acheta domesticus) with altered color patterns. We found no support for the motion dazzle effect as striped crickets did not fare better than solid colored ones. Crickets that spent more time moving, however, were more likely to be eaten. Our results suggest that motion specialized visual predators such as toads overcome the motion dazzle effect and impose stronger selection pressure on prey behavior than on coloration. These findings emphasize the importance of sensory specializations of predators in mediating antipredator strategies.
各地的捕食者都会对其猎物的形态和行为施加强大的选择压力，但由此产生的反捕食者适应能力在不同物种间差异很大。对猎物物种的适应性色彩的研究通常集中在保护色或警戒色的猎物上，很少考虑可口的移动猎物的颜色模式。有人提出复杂的颜色模式会降低视觉捕食者捕捉移动猎物的能力（运动眩晕效应）。然而，对这一假设的大多数支持来自对人类受试者和模拟猎物的实验。我们首次使用自然捕食者（蔗蟾，海蟾蜍）和颜色模式改变的活体猎物（家蟋蟀）来测试运动眩晕效应。我们没有发现运动眩晕效应的证据，因为有条纹的蟋蟀并不比纯色的蟋蟀表现更好。然而，活动时间更长的蟋蟀更有可能被吃掉。我们的结果表明，像蟾蜍这样具有运动特异性视觉的捕食者能够克服运动眩晕效应，并且对猎物行为施加比对颜色更强的选择压力。这些发现强调了捕食者的感官特化在介导反捕食者策略中的重要性。
