Data from: Predator-vole interactions in boreal Europe: the necessity of small mustelid predation in summer

The cyclic population dynamics of vole and predator communities is a key phenomenon in the northern ecosystem, and it appears to be influenced by climate change. Reports of collapsing rodent cycles have implicated warmer winters, which weaken the interaction between voles and their specialist subnivean predators, as a causal factor. Using population data collected throughout Finland during 1986-2011, we analyze the spatiotemporal 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 the vole population cyclicity is dependent on predator-prey interactions during winter. Our results support the importance of 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, while a strong impact of small mustelids during summers appears highly influential to cyclic vole dynamics, deteriorating winter conditions are not a viable explanation for collapsing small mammal population cycles.