Population fluctuations of Field voles (Microtus): a background to the problems involved in predicting vole plagues.
The course of various investigations into vole cycles is briefly reviewed and it is shown that an increasing proportion of workers are looking for intrinsic mechanisms of control which might cause the periodic fluctuations; however, no single line of investigation can be said to dominate the field and extrinsic factors such as food supply or predation could be heavily involved. The majority of work has failed to take into account the spatial aspects of these cycles and future work in this field might resolve some of the conflicts about the demographic aspects. As yet few workers have considered vole cycles on a geographical scale and just how these major changes in abundance relate to the local fluctuations of smaller populations is not known.
Various methods used to measure vole densities are reviewed and suggestions are made on how they can be used to provide information on different aspects of vole population studies.