Life history theory predicts that individuals will differ in their risk-taking behavior according to their expected future fitness. Understanding consequences of such individual variation within a behavioral trait is crucial in explaining potential trade-offs between different traits and in predicting future dynamics in changing environments. Here, we studied individuals in a wild arctic fox population to explore if (1) individual variation in risk-taking behaviors of adult arctic foxes and in stress-dealing behaviors of their juveniles exist and are consistent over time to verify the existence of personality traits; (2) those behavioral traits in adults and juveniles are correlated; (3) they can explain fitness-related components (i.e., juvenile physical condition, mortality rate). We presented simple field experiments assessing behavioral traits by observing adult reactions toward approaching observers, and juvenile behaviors while trapping. Through the experiments, we found highly consistent individual variation of adults in vigilance and boldness levels, and more flexible juvenile behavioral traits categorized as investigating, passive, and escaping. The offspring of bolder adults exhibited more investigating behaviors and were less passive than the offspring of shy adults. Juvenile physical condition was not related to their mortality nor any behavioral traits of either parents or themselves. Lastly, highly investigating and active juveniles with bold parents had significantly lower mortality rates. This shows that interactions between parent personality and juvenile behavioral traits affect a fitness-related component in the life history of individuals. The recent surge of interest in consistent individual difference in behavior, also called as animal personality, has already focused on its fitness consequences, but few studies have investigated the interactions between parent and offspring personality, and their ecological consequences. Moreover, this has rarely been studied in wild canids. The arctic fox is a charismatic species showing wide individual variation in behaviors. They live in highly fluctuating tundra ecosystems providing different selection regimes, making it even more eco-evolutionarily intriguing. Yet, few studies looked into behavioral traits and their importance in this system. While introducing simple methods to improve personality research in the wild, we provide a unique example of how variation in both parents and their juveniles collectively works for group dynamics in a cyclic population. This provides a firm basic for understanding behavior-mediated dynamics and opens up broader questions on how fluctuating environments exert varying pressures on individual differences.

中文翻译：

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父母性格与北极狐（Vulpes lagopus）的幼年死亡率和压力行为有关

生活史理论预测，个人会根据他们预期的未来健康状况，在冒险行为上有所不同。了解行为特征中这种个体变异的后果对于解释不同特征之间的潜在权衡以及预测不断变化的环境中的未来动态至关重要。在这里，我们研究了野生北极狐种群中的个体，以探索 (1) 成年北极狐的冒险行为和幼年北极狐应对压力行为的个体差异是否存在并且随着时间的推移保持一致，以验证个性特征的存在; (2)成体与幼体的行为特征具有相关性；(3)可以解释与健康相关的组成部分（即青少年身体状况、死亡率）。我们通过观察成年人对接近观察者的反应和诱捕时的青少年行为，展示了评估行为特征的简单现场实验。通过实验，我们发现成年人在警惕性和大胆程度方面的个体差异高度一致，而青少年的行为特征更加灵活，分为调查、被动和逃避。与害羞的成年人的后代相比，胆大的成年人的后代表现出更多的调查行为，并且不那么被动。少年身体状况与他们的死亡率无关，也与父母或他们自己的任何行为特征无关。最后，具有大胆父母的高度调查和活跃的青少年的死亡率显着降低。这表明父母人格和青少年行为特征之间的相互作用会影响个体生活史中与健康相关的组成部分。最近对一致的个体行为差异（也称为动物个性）的兴趣激增，已经集中在其适应性后果上，但很少有研究调查父母和后代个性之间的相互作用及其生态后果。此外，这很少在野生犬科动物中进行过研究。北极狐是一种魅力非凡的物种，在行为上表现出广泛的个体差异。它们生活在高度波动的苔原生态系统中，提供不同的选择机制，使其在生态进化上更加有趣。然而，很少有研究关注行为特征及其在该系统中的重要性。在介绍改善野外个性研究的简单方法的同时，我们提供了一个独特的例子，说明父母及其青少年的变异如何共同作用于循环种群中的群体动态。这为理解行为介导的动态提供了坚实的基础，并提出了关于波动环境如何对个体差异施加不同压力的更广泛问题。