How ecological structural elements curb outbreaks of fossorial arvicoline rodents in European farmlands

Abstract Outbreaks of fossorial arvicoline rodents have plagued temperate European farmlands throughout history, causing large-scale crop loss and forming reservoirs for zoonotic pathogens. Industrialisation of agricultural practices has led to an increase of agricultural field sizes in Europe, coinciding with the removal of ecological structural elements (ESE) such as hedgerows, tree lines, and bushes. This has promoted both the probability and the spatial extent of vole outbreaks. Here, we review the role of ESE in farmlands in shaping outbreak dynamics of the fossorial vole across field, landscape and regional scales. ESE play a crucial role in the scale and connectivity of vole habitats, and influence competition and predation. Open landscapes with no or few ESE such as grasslands, perennial crops and pastures, form optimal vole habitats and are linked to multi-annual cycling and outbreaks of fossorial vole populations. Conversely, ESE exert a limiting force on population growth and the likelihood of outbreaks. ESE create physical barriers between vole populations and offer corridors, habitats and perching sites for predators of the common vole. Woody ESE, such as hedgerows, forest patches and strips, as well as rural built-up structures, attract generalist predators and enhance edge effects. ESE can be used as an effective management measure to curb and reduce outbreak hazards in farmland. Vole outbreak hazard predictions in Europe can be strengthened by integrating ESE spatial configuration derived from high-resolution remote sensing data (e.g. LiDAR) with long-term (> 6 years) and multi-scale monitoring of vole population dynamics.