N.C. Stenseth, O.N. Bjørnstad and W. Falck: Is spacing behaviour coupled with predation causing the microtine density cycle? A synthesis emerging from combining process-oriented and pattern-oriented studies.

Proceedings of Royal Society London B (1996) 263:1423-1435.


Current ecological information on periodically fluctuating microtine populations are demonstrated to support a hypothesis involving both predation and intrinsic self-regulation as necessary and sufficient factors for explaining the 'microtine density cycle'. The structure of time series is largely two dimensional with strong delayed density-dependence. Together with recent field studies on rodent demography, our modelling suggests that trophic interaction is a likely candidate to generate the dimensionality observed for Northern microtine rodent dynamics. It is shown that the trophic interaction must be fairly strong. This suggests that specialist predation is the most probable among the classes of trophic interactions. We also argue that some - but not too strong - self-regulation must occur in order to generate the structure of all available time series on Northern European microtines.

Key words: Rodents; Population dynamics; Time series; Social organisation; Dynamic dimension