Yli-Renko Maria, Pettay Jenni E, Vesakoski Outi
Department of Biology, FIN-20014 University of Turku, Finland.
Department of Biology, FIN-20014 University of Turku, Finland.
Behav Processes. 2018 Mar;148:20-26. doi: 10.1016/j.beproc.2017.12.023. Epub 2017 Dec 27.
Optimal life-history strategies are currently considered to be a major driving force for the maintenance of animal personalities. In this experimental study we tested whether naturally occurring predation causes personality-dependent mortality of a marine isopod (Idotea balthica), which could maintain personality variation in nature. Moreover, as isopods are known to have sex-differences in behaviour, we were interested in whether personality-dependent predation was sex-specific. We also hypothesised that predation pressure among personality types could vary according to habitat type, as it has been shown in correlative studies that habitat may influence personality variation. We used natural predator (European perch Perca fluviatilis) of I. balthica and studied relative mortality of males and females with a different personality types in laboratory settings with two different habitats. We found that survival in males was lower than in females for high active individuals. Moreover, survival under predation was linked to body size differently in females and males. This, however, depended on personality class as larger size was advantageous for low-active males and middle- and high-active females. Conversely, smaller size was advantageous for low-active females and middle-active males. Size did not affect survival in high-active males. Our results suggest that predation can encourage life-history differences between sexes leading to different optimal life-history strategies and also maintains consistent activity for both sexes.
目前认为，最优生活史策略是维持动物个性的主要驱动力。在这项实验研究中，我们测试了自然发生的捕食是否会导致一种海洋等足类动物（巴尔蒂卡等足虫）出现依赖个性的死亡，而这可能会在自然界中维持个性差异。此外，由于已知等足类动物在行为上存在性别差异，我们想了解依赖个性的捕食是否具有性别特异性。我们还假设，个性类型之间的捕食压力可能会因栖息地类型而异，因为在相关研究中已经表明栖息地可能会影响个性差异。我们使用了巴尔蒂卡等足虫的自然捕食者（欧洲鲈鱼），并在两种不同栖息地的实验室环境中研究了不同个性类型的雄性和雌性的相对死亡率。我们发现，高活跃个体中，雄性的存活率低于雌性。此外，在捕食情况下，雌性和雄性的生存与体型的关联不同。然而，这取决于个性类别，因为较大体型对低活跃雄性以及中等活跃和高活跃雌性有利。相反，较小体型对低活跃雌性和中等活跃雄性有利。体型对高活跃雄性的生存没有影响。我们的结果表明，捕食可以促使两性之间出现生活史差异，导致不同的最优生活史策略，并且还能维持两性一致的活动水平。
