Consistent demographic trends in Savi's pine vole between two distant areas in central Italy

Abstract

The Savi's pine vole, Microtus savii is an Italian species living in grasslands, both natural and anthropogenic (i.e. agroecosystems) where it is generally considered a pest because it may damage crops and orchards. As for most rodent pests, the extent of the damage might depend on population density and temporal food availability (e.g. Brown et al. 2007, Jacob & Tkadlec 2010). However, data on demographic parameters are not available, making ecologically-based management strategies difficult to plan. Therefore, we conducted a study on Savi's pine vole demography for one year in two study areas in central Italy using capture-mark-recapture method. Density values ranged from 3 to 32 ind./ha, the highest population densities occurred in October, while the lowest occurred in February-April in both study areas. Turnover rates of both populations were very high, with time of residency usually no longer than two months. Juveniles' survival was constant in both study areas, but it differed between the two populations regarding adults. The two populations showed similar demographic trends along the year with relatively small intra-annual fluctuations. The breeding season covered the whole year in both areas. The results here presented contribute to add meaningful information about this poorly known species, and could be useful to plan population control strategies for this rodent in agroecosystems.