Abstract

Predation is a major source of selection and prey are known to modify their behavior depending on their past experiences and the current perceived risk. Within a species, variation in experience and in the response to perceived risk combine to explain variation in personality and individual plasticity. Between species, variation in personality and plasticity might also be the evolutionary consequence of different selective regimes. In this study, we describe the anti-predator behavior of two closely related brown frogs, Rana dalmatina and Rana latastei, and compare their structures of personality variation. We raised tadpoles in a common garden experiment with either fish, dragonfly larvae, or no predators. Tadpoles were then repeatedly tested in the presence of the three acute stimuli and their behavioral variation was described in terms of quantity and quality of movements and of path sinuosity. In these tests, tadpoles of both species and ontogenetic treatments responded flexibly to predators by moving less, faster, and with more tortuous movements, and tadpoles raised with predators tended to move even faster. Independent of the acute treatment, R. dalmatina moved more and faster than R. latastei and the differences were larger without than with predators, demonstrating its higher plasticity. At the individual level, the two species showed qualitatively similar but quantitatively different structures of personality variation. R. dalmatina, more active, faster, and more plastic than R. latastei, showed also higher repeatability and a larger behavioral variation both among and within individuals.

Significance statement

Predators are a major source of selection and preys have evolved the ability to flexibly respond to them. These responses often vary among species, because of their different evolutionary histories, and among individuals, because of their different experiences. We analyzed both these sources of behavioral variation in two closely related brown frogs, Rana dalmatina and R. latastei. We raised tadpoles either with or without predators and tested them in open field trials both with and without predators. The effects of the raising environment were similar in the two species, whereas the effects of the testing arena differed. Both species decreased activity and increased speed and sinuosity with predators, but R. dalmatina moved always more and faster than R. latastei and it showed higher plasticity, larger variation among and within individuals, and relatively higher values in repeatability.

中文翻译：

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两种棕色青蛙的反捕食者行为：平均行为和动物人格变异结构的差异

摘要

捕食是选择的主要来源，众所周知，猎物会根据过去的经验和当前感知的风险来改变自己的行为。在一个物种内，经验的变化和对感知风险的反应的变化结合起来解释了性格和个体可塑性的变化。物种之间，个性和可塑性的差异也可能是不同选择机制的进化结果。在这项研究中，我们描述了两种密切相关的棕蛙（ Rana dalmatina和Rana latastei）的反捕食行为，并比较他们的人格变异结构。我们在一个常见的花园实验中饲养蝌蚪，其中要么有鱼、蜻蜓幼虫，要么没有捕食者。然后在三种急性刺激存在下对蝌蚪进行反复测试，并根据运动的数量和质量以及路径蜿蜒度来描述它们的行为变化。在这些测试中，不同物种和个体发育处理的蝌蚪都通过移动更少、更快和更曲折的运动来灵活地响应捕食者，并且与捕食者一起饲养的蝌蚪往往移动得更快。与急性治疗无关，达尔马提纳河豚（R. dalmatina）比拉氏河豚（R. latastei）移动得更多、更快没有捕食者的情况下的差异比有捕食者的情况下的差异更大，这表明其可塑性更高。在个体层面上，这两个物种表现出质上相似但量上不同的人格变异结构。R. dalmatina比R. latastei更活跃、更快、更具可塑性，并且在个体之间和个体内部也表现出更高的重复性和更大的行为变异。

意义陈述

捕食者是选择的主要来源，猎物已经进化出灵活应对捕食者的能力。这些反应往往因物种不同而不同，因为它们有不同的进化历史，而不同个体则因经历不同而有所不同。我们分析了两种密切相关的褐蛙（ Rana dalmatina和R. latastei）的行为变异来源。我们在有或没有捕食者的情况下饲养蝌蚪，并在有或没有捕食者的情况下在露天试验中对它们进行测试。饲养环境对这两个物种的影响相似，而测试环境的影响则不同。这两个物种都减少了与捕食者的活动，并增加了速度和蜿蜒度，但达尔马提纳红蜥的移动总是比捕食者更多更快。R. latastei及其表现出较高的可塑性、个体间和个体内较大的变异性以及相对较高的重复性值。