Revealed by conspicuousness: distractive markings reduce camouflage
Revealed by conspicuousness: distractive markings reduce camouflage
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DOI：
10.1093/beheco/ars156
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发表时间：
2013-01-01
影响因子：
2.4
通讯作者：
Chadwick, Sarah L.
中科院分区：
文献类型：
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作者：
Stevens, Martin;Marshall, Kate L. A.;Chadwick, Sarah L.
动物伪装是自然选择的教科书范例。尽管取得了实质性的进展，但一个历史理论仍然存在争议：明显的“分散注意力”的标记将捕食者的注意力从猎物的轮廓上引开，从而防止被发现。在这里，我们提出了来自4个实验的证据来解决这一争议。在野外实验中，我们测量了鸟类捕食人工隐蔽猎物，无论是无标记或分散标记的各种属性（数量，颜色和位置）。猎物与3高对比度分散标记，并与标记位于远离身体轮廓，遭受减少的生存与无标记的控制或猎物与低对比度标记。不同颜色的单个小标记对目标的生存没有影响。在2个基于计算机的实验中，人类受试者搜索隐藏的目标，与对照组相比，各种类型（数量，大小和位置）的分心标记减少了检测时间。这种效果是最大的目标，有大或3标记。此外，小而集中的标记有助于更快的学习。因此，这两个实验方法表明，分心标记是有害的伪装，既有利于初始检测和提高捕食者学习的速度。我们的实验还表明，学习的伪装猎物是依赖于伪装的类型。与当前和历史上的讨论相反，显眼的标记更有可能损害伪装而不是增强伪装，这对猎物着色的优化具有重要意义。
Animal camouflage is a textbook example of natural selection. Despite substantial progress, one historical theory remains controversial: that conspicuous "distractive" markings draw predator attention away from the prey outline, preventing detection. Here, we present evidence from 4 experiments to resolve this controversy. In field experiments, we measured bird predation on artificial cryptic prey that were either unmarked or had distractive markings of various attributes (number, color, and location). Prey with 3 high-contrast distractive markings, and with markings located away from the body outline, suffered reduced survival compared with unmarked controls or prey with low-contrast markings. There was no effect of small single markings with different colors on the survival of targets. In 2 computer-based experiments with human subjects searching for hidden targets, distractive markings of various types (number, size, and location) reduced detection times compared with controls. This effect was greatest for targets that had large or 3 markings. In addition, small and centrally placed markings facilitated faster learning. Therefore, these 2 experimental approaches show that distractive markings are detrimental to camouflage, both facilitating initial detection and increasing the speed of predator learning. Our experiments also suggest that learning of camouflaged prey is dependent on the type of camouflage present. Contrary to current and historical discussion, conspicuous markings are more likely to impair camouflage than enhance it, presenting important implications for the optimization of prey coloration in general.