title: Predator-vole interactions in Northern Europe: the role of small mustelids revised.
abstract: 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.
authors.affiliation: Department of Biological and Environmental Science, FI-40014 University of Jyväskylä, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Korpela
authors.affiliation: Finnish Game and Fisheries Research Institute, FI-90014 University of Oulu, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Helle
authors.affiliation: Vantaa Research Unit, Finnish Forest Research Institute, FI-01301 Vantaa, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Henttonen
authors.affiliation: Department of Biology, FI-20014 University of Turku, Finland.
authors.forename: Erkki
authors.initials: E
authors.lastname: Korpimäki
authors.affiliation: Department of Biological and Environmental Science, FI-40014 University of Jyväskylä, Finland.
authors.forename: Esa
authors.initials: E
authors.lastname: Koskela
authors.affiliation: Department of Biosciences University of Helsinki, Finland.
authors.forename: Otso
authors.initials: O
authors.lastname: Ovaskainen
authors.affiliation: Department of Biosciences University of Helsinki, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Pietiäinen
authors.affiliation: Lammi Biological Station, University of Helsinki, FI-16900 Lammi, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Sundell
authors.affiliation: Finnish Museum of Natural History, FI-00014 University of Helsinki, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Valkama
authors.affiliation: Suonenjoki Research Unit, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland otso.huitu@metla.fi.
authors.forename: Otso
authors.initials: O
authors.lastname: Huitu
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000502:physiology*; D001717:Birds / Q000502:physiology*; D057231:Climate Change; D005060:Europe; D008322:Mammals / Q000502:physiology*; D008962:Models, Theoretical; D011156:Population Density; D011157:Population Dynamics; D011235:Predatory Behavior
keywords: density dependence; population cycles; population dynamics; population growth rate