From pattern to process? Dual travelling waves, with contrasting propagation speeds, best describe a self-organised spatio-temporal pattern in population growth of a cyclic rodent.

The dynamics of cyclic populations distributed in space result from the relative strength of synchronising influences and the limited dispersal of destabilising factors (activators and inhibitors), known to cause multi-annual population cycles. However, while each of these have been well studied in isolation, there is limited empirical evidence of how the processes of synchronisation and activation-inhibition act together, largely owing to the scarcity of datasets with sufficient spatial and temporal scale and resolution. We assessed a variety of models that could be underlying the spatio-temporal pattern, designed to capture both theoretical and empirical understandings of travelling waves using large-scale (>35,000 km2 ), multi-year (2011-2017) field monitoring data on abundances of common vole (Microtus arvalis), a cyclic agricultural rodent pest. We found most support for a pattern formed from the summation of two radial travelling waves with contrasting speeds that together describe population growth rates across the region.

Unintentional effects of environmentally-friendly farming practices: Arising conflicts between zero-tillage and a crop pest, the common vole (Microtus arvalis).

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.