Vole cycles and predation in temperate and boreal zones of Europe
Article first published online: 10 OCT 2005
Journal of Animal Ecology
Volume 74, Issue 6, pages 1150–1159, November 2005
How to Cite
KORPIMÄKI, E., OKSANEN, L., OKSANEN, T., KLEMOLA, T., NORRDAHL, K. and BANKS, P. B. (2005), Vole cycles and predation in temperate and boreal zones of Europe. Journal of Animal Ecology, 74: 1150–1159. doi: 10.1111/j.1365-2656.2005.01015.x
- Issue published online: 2 NOV 2005
- Article first published online: 10 OCT 2005
- Received 19 October 2004; accepted 5 July 2005
- functional response;
- generalist predators;
- population cycles;
- specialist predators
- 1Graham & Lambin (2002) have reported on a weasel-reduction experiment, concluding that the impact of weasel predation on field vole survival was neither sufficient nor necessary to initiate and drive the cyclic decline of field vole populations in Kielder Forest, northern England. They also stated that their findings contradict conclusively the specialist predator hypothesis put forward to explain population cycles of voles in North Europe.
- 2Straightforward inferences from Kielder Forest to the northern boreal zone are misleading, because the population cycles of voles in Kielder Forest differ essentially from North European vole cycles. The low amplitude of the vole cycles in Kielder Forest, their restricted spatial synchrony in comparison to northern Europe and the virtual lack of interspecific synchrony in Kielder Forest suggest that there are essential differences between the mechanisms responsible for the two types of cyclic fluctuations of voles.
- 3The weasel-reduction experiment may provide a misleading picture on the role of predators, even in the Kielder Forest cycle. The experimental reduction of weasels alone may not stop the population decline of voles, because competing larger predators are expected to increase their hunting in the weasel-reduction areas. The small spatial scale of the experiment, which produced only slight, short-term differences in weasel densities between reduction and control areas, also suggests that other predators could have compensated easily for the weasels that were removed.
- 4We propose a new version of the predation hypothesis to explain low-amplitude population cycles of voles in temperate Europe, including the Kielder Forest. The interaction between generalist predators and vole populations might account for these cycles because generalists can have a functional response that is destabilizing in the neighbourhood of the equilibrium point. As most generalists are orders of magnitude larger than weasels, and thus need much more food for survival, generalist-driven cycles should be characterized by high prey minima, as observed in Kielder Forest.