Common voles are a main European facultative, fossorial, farmland rodent pest that can greatly reduce crop yields during population outbreaks. Crop protection against common voles is a complex task that requires the consideration of a set of preventive and control measures within an integrated pest management strategy. A possible option could be to modify farming practices to reduce the availability of refuges for rodents and the damage to crops that they subsequently cause. Farming, however, must simultaneously meet multiple goals including the reduction of the carbon (C) emissions, soil erosion and water use, and the improvement of soil quality. Crop establishment through conservation agriculture strategies, like zero-tillage, would reduce crop management investment, but is also promoted in many regions to reduce C emissions and increase soil organic matter. It could, however, create favourable refuge habitats for fossorial rodent crop pests, like common voles, benefitting from reduced soil disturbance between crop rotations and thus increasing burrow persistence. Assessing the impact that tillage practices, their interaction with different crops and the influence of proximity to potential common vole sources, have on common vole occupancy could provide a valuable tool within an integrated management strategy. Using a 2-ha experimental field with 62 plots 180 m2 (each roughly matching common vole home range size) located experimental plots in north-western Spain, we tested how tillage practices, crop type (wheat, barley, vetch, Narbonne vetch, pea and fallow) and distances from possible colonization sources affect field use by common vole during low population density conditions. Our results show that tillage practices have more influence on common vole occurrence (zero tillage > reduced and conventional tillage) than other aspects such as crop type thus supporting the hypothesis that tillage practices play a key role in common vole habitat use.
Bibliographical noteWe are grateful to Dra. Aurora Sombrero Sacristán (ITACyL) and her staff for allowing this experiment to take place parallel to their own and for providing information on the experimental field for this research. We would also like to thank Dr Alex Douglas for his help with the statistical analysis, and K. Barré and an anonymous reviewer for help comments on the MS. This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/M010996/1], through Eastbio DTP. The surveys were carried out under ITACYL project 2007/2155. Sir Maitland Mackie Scholarship provided additional funding to the lead author, D. Roos, for which he is grateful. The authors report no conflict of interests.
- outbreak management