Data from: Multi-trait mimicry and the relative salience of individual traits

Mimicry occurs when one species gains protection from predators by resembling an unprofitable model species. The degree of mimic-model similarity is variable in nature and is closely related to the number of traits that the mimic shares with its model. Here, we experimentally test the hypothesis that the relative salience of traits, as perceived by a predator, is an important determinant of the degree of mimic-model similarity required for successful mimicry. We manipulated the relative salience of the traits of a two-trait artificial model prey, and subsequently tested the survival of mimics of the different traits. The unrewarded model prey had two colour traits, black and blue, and the rewarded prey had two combinations of green, brown and grey shades. Blue tits were used as predators. We found that the birds perceived the black and blue traits similarly salient in one treatment, and mimic-model similarity in both traits was then required for high mimic success. In a second treatment, the blue trait was the most salient trait, and mimic-model similarity in this trait alone achieved high success. Our results thus support the idea that similar salience of model traits can explain the occurrence of multi-trait mimicry.拟态（Mimicry）指某一物种通过模仿对捕食者而言无收益的模式物种，从而获得躲避捕食者保护的现象。自然界中，拟态者与模式物种的相似程度存在自然变异，且与拟态者共享的模式物种性状数量密切相关。本研究通过实验验证了下述假说：捕食者所感知到的性状相对显著性，是成功拟态所需的拟态-模式物种相似程度的重要决定因素。我们对具有两种性状的人工模式猎物的性状相对显著性进行了操控，随后针对不同性状的拟态者的存活情况开展了检测。无收益模式猎物具备黑色与蓝色两种颜色性状，而有收益猎物则拥有绿、棕、灰三种色调的两种组合。本实验以蓝山雀（Blue tits）作为捕食者模型。实验结果显示，在一组处理中，蓝山雀对黑色与蓝色性状的感知显著性相近，此时若要实现高拟态成功率，拟态者需同时在两种性状上与模式物种保持相似。在另一组处理中，蓝色性状的感知显著性最高，此时仅需拟态者在该单一性状上与模式物种保持相似，即可获得较高的拟态成功率。综上，本研究结果支持"模式物种性状的相似显著性可解释多性状拟态的发生"这一观点。