Predators around: should I stay or should I go? Mum knows it. Role of maternal effect in an adaptive dispersal decision.

动物的迁徙是指个体离开它们以前生活的栖息地。这一看似简单的现象对一系列关键的生态过程产生了重要影响，并最终影响了物种的持久性。事实上，通过分散，动物在现代多样化和多变的景观中找到了合适的栖息地。分散是一个个体的决定，在利益和迁移成本之间的平衡，这与个体表型和生态环境有关。面对相同的当地条件，个体会以不同的方式分散，以最大限度地提高生存和繁殖的成功率。评估重要的环境因素，例如被捕食的危险，可能是困难的，特别是在那些主要由幼鱼进行传播的物种中。在这方面，母亲在相关的繁殖活动中收到的捕食者线索代表了新生儿的重要信息来源。因此，自然选择应该偏爱那些能够利用出生环境的信息来微调后代分散趋势的雌性。这种母性调节尤其可能发生在胎生脊椎动物中，因为在怀孕期间母体和胎儿之间有密切的接触。因此，捕食者诱导的母体效应会影响后代的扩散决策，促进它们适应当地的捕食环境。本项目旨在阐明，如果怀孕的普通蜥蜴（Zootoca vivipara）利用捕食风险线索影响其后代的扩散趋势和整体表型。我将测试这些假设，1)操纵母亲和后代感知到的被捕食风险，2)在高度逼真的半自然环境中测量后代的扩散、生长、生存和繁殖。这是脊椎动物中母亲对后代适应性捕食依赖扩散影响的第一次实证研究。

Animal dispersal is the movement of individuals away from their previous living habitat. This apparently simple phenomenon has important consequences over a series of key ecological processes and, ultimately, on species persistence. Indeed, by means of dispersal, animals find suitable habitats within the modern heterogeneous and changeable landscapes. Dispersal is an individual decision, over the balance between benefits and costs of moving, which varies in relation to individual phenotype and ecological context. Facing the same local conditions individuals will disperse differently in order to maximize their survival and reproductive success.The evaluation of vital environmental factors, such as predation risk, may prove difficult, particularly in species in which dispersal is carried out mostly by juveniles. To this respect, the predator cues received by the mother during relevant reproductive events represent a vital source of information for the newborns. Therefore, natural selection should favour females that are able to use such information on the natal environment to fine-tune the dispersal tendencies of their offspring. This maternal regulation may occur, a fortiori, in viviparous vertebrates, because of the close contact between mother and fetus during pregnancy. Predator-induced maternal effect would thus influence offspring dispersal decisions, facilitating their adaptation to the local predatory environment. This project aims at clarifying, if pregnant common lizards (Zootoca vivipara) use predation risk cues to influence the dispersal tendencies and overall phenotype of their offspring. I will test these hypotheses, 1) manipulating perceived predation risk in both mothers and offspring and 2) measuring offspring dispersal, growth, survival and reproduction in a highly realistic semi-natural setting. This is the first empirical study of maternal influence over offspring adaptive predation-dependent dispersal in a vertebrate.