Data from: Predator–vole interactions in northern Europe: the role of small mustelids revised

The cyclic population dynamics of vole and predator communities is a key phenomenon in northern ecosystems, and it appears to be influenced by climate change. Reports of collapsing rodent cycles have attributed the changes to warmer winters, which weaken the interaction between voles and their specialist subnivean predators. Using population data collected throughout Finland during 1986–2011, we analyse the spatio-temporal variation in the interactions between populations of voles and specialist, generalist and avian predators, and investigate by simulations the roles of the different predators in the vole cycle. We test the hypothesis that vole population cyclicity is dependent on predator–prey interactions during winter. Our results support the importance of the small mustelids for the vole cycle. However, weakening specialist predation during winters, or an increase in generalist predation, was not associated with the loss of cyclicity. Strengthening of delayed density dependence coincided with strengthening small mustelid influence on the summer population growth rates of voles. In conclusion, a strong impact of small mustelids during summers appears highly influential to vole population dynamics, and deteriorating winter conditions are not a viable explanation for collapsing small mammal population cycles.田鼠与捕食者群落的种群周期性动态是北方生态系统的核心现象之一，且其变化似乎受气候变化调控。已有研究报道啮齿类种群周期出现崩溃，将此类变化归因于暖冬——暖冬会削弱田鼠与其特化雪下捕食者（specialist subnivean predators）之间的种间相互作用。本研究依托1986—2011年在芬兰全境采集的种群数据，分析了田鼠种群与特化捕食者、泛化捕食者及鸟类捕食者之间相互作用的时空变异，并通过数值模拟探究了不同捕食者类群在田鼠种群周期中的作用。我们验证了“田鼠种群周期性依赖于冬季捕食者-猎物相互作用”这一研究假说。研究结果证实了小型鼬科动物（small mustelids）对田鼠种群周期的重要调控作用。不过，冬季特化捕食压力的减弱或泛化捕食压力的上升，与田鼠种群周期性的丧失并无显著关联。延迟密度依赖性（delayed density dependence）的增强，与小型鼬科动物对田鼠夏季种群增长率的影响提升同时发生。综上，小型鼬科动物在夏季的强调控作用对田鼠种群动态具有关键影响，而冬季环境恶化并非小型哺乳动物种群周期崩溃的合理解释。