Erik Framstad

TL;DR: It is shown that winter weather and snow conditions, together with density dependence in the net population growth rate, account for the observed population dynamics of the rodent community dominated by lemmings in an alpine Norwegian core habitat between 1970 and 1997, and predict the observed absence of rodent peak years after 1994.

TL;DR: Using a large compilation of time series of vole abundances, it is demonstrated consistent cycle amplitude dampening associated with a reduction in winter population growth, although regulatory processes responsible for cyclicity have not been lost.

TL;DR: In this paper, the authors have analysed yearly changes in fall abundances for lemmings over 25 years from two local mountain sites in South Norway and found that the time series appear to have an underlying nonlinear structure of order two.

TL;DR: It is demonstrated that the population dynamics of Norwegian lemmings is both phase– and density–dependent and stochasticity is seen to play an important role in the determination of the periodicity.

TL;DR: In this paper, the reproductive effort as a function of the reproducing individual's weight and number of fetuses has been estimated based on models for energy requirements of reproducing females of the common vole Microtus arvalis.