Trap type and positioning: How to trap Savi's pine voles using the tunnel system

Savi's pine vole, Microtus savii, is the most widespread Italian vole species, an important rodent pest of agriculture, and yet one of the least studied species. One of the reasons for this gap in knowledge is that members of this species are quite difficult to capture with standard trapping procedures, being fossorial and rarely active above ground. For this reason, we developed a protocol that maximizes trapping success. This method requires the identification of the active tunnel holes and the placement of the traps directly in front of the exits. We also compared capture and recapture rates of Savi’s pine voles in three different trap types: INRA, Longworth and Ugglan. If properly equipped with food and nesting material, INRA, Longworth and Ugglan traps showed similar capture rates, but the recapture rate of Ugglan traps was the highest of the three kinds of traps. These results, in combination with the species´ fossorial and social habits, lead us to conclude that Ugglan traps are the best suited for studies on Savi´s pine voles. Our results may have implications for planning and implementing management strategies based on traps rather than rodenticides, as well as field studies on other fossorial small mammals.