Abstract Invasive predators often impose devastating selection pressures on native prey species. However, their effects can be regionally dependent and influenced by the local ecological conditions of their invaded habitats. Evolved behavioral phenotypes are important mechanisms by which prey adapt to the presence of novel predators. Here, we asked how behavior and behavioral plasticity of threespine stickleback (Gasterosteus aculeatus) populations have evolved following the introduction of the invasive predator, northern pike (Esox lucius). We examined the behavior of F1 offspring generated from three pike-free and three pike-invaded populations and measured how stickleback activity and plant use behaviors, and their plasticity, have evolved following pike introduction. To evaluate plasticity, we exposed juvenile stickleback to predator cues during their first year of development and then evaluated how this repeated exposure influenced behavioral responses to an artificial predation event. We found no overarching effect of pike in either evolved behaviors or behavioral plasticity, and no evidence for the presence of developmental plasticity. Furthermore, we found that depending on the phenotype, pike-invaded stickleback populations have either more or less among-population variation than pike-free populations. Our results suggest that evolution in response to invasive predators may be hidden by local adaptation when enough populations are studied.

中文翻译：

---

北梭子鱼入侵后，没有迹象表明三棘棘鱼的行为进化

摘要 入侵性捕食者经常对本地猎物物种施加毁灭性的选择压力。然而，它们的影响可能取决于区域，并受其入侵栖息地的当地生态条件的影响。进化的行为表型是猎物适应新捕食者存在的重要机制。在这里，我们询问了三棘棘鱼（Gasterosteus aculeatus）种群的行为和行为可塑性在引入入侵性捕食者北梭子鱼（Esox lucius）后是如何进化的。我们检查了由三个无梭子鱼和三个入侵梭子鱼种群产生的 F1 后代的行为，并测量了棘鱼活动和植物使用行为及其可塑性在引入梭子鱼后如何演变。为了评估可塑性，我们在幼年棘鱼发育的第一年将它们暴露于捕食者的线索，然后评估这种反复暴露如何影响对人工捕食事件的行为反应。我们发现梭子鱼在进化行为或行为可塑性中没有总体影响，也没有证据表明存在发育可塑性。此外，我们发现，根据表型，梭鱼入侵的棘鱼种群比无梭鱼种群具有或多或少的种群间变异。我们的研究结果表明，当研究足够多的种群时，对入侵性捕食者的进化反应可能会被局部适应所掩盖。我们发现梭子鱼在进化行为或行为可塑性中没有总体影响，也没有证据表明存在发育可塑性。此外，我们发现，根据表型，梭鱼入侵的棘鱼种群比无梭鱼种群具有或多或少的种群间变异。我们的研究结果表明，当研究足够多的种群时，对入侵性捕食者的进化反应可能会被局部适应所掩盖。我们发现梭子鱼在进化行为或行为可塑性中没有总体影响，也没有证据表明存在发育可塑性。此外，我们发现，根据表型，梭鱼入侵的棘鱼种群比无梭鱼种群具有或多或少的种群间变异。我们的研究结果表明，当研究足够多的种群时，对入侵性捕食者的进化反应可能会被局部适应所掩盖。