From biology to management of Savi's pine vole (Microtus savii)

A model for voles interference in cultivated orchards

We consider a dynamical system involving seven populations to model the presence of voles in a cultivated orchard. The plant population is stratified by age (three groups) and by health status (being damaged or not). The last equation models the voles with a modified logistic equation with Allee effect, where the modification takes into account the disturbance provided by the human activity on the orchard. Both an analytical investigation and numerical simulations on a case study are presented. The latter support the observed differences in the literature, in terms of number of voles, between cultivated and uncultivated fields.

Ecological Analysis of the Helminth Community of Microtus lusitanicus (Gerbe, 1879) (Rodentia) in Asturias (NW Spain)

The Lusitanian pine vole, Microtus lusitanicus, an endemic fossorial rodent of the Iberian Peninsula, has a burrowing behaviour and prefers to live underground. It feeds on bark and roots causing severe damage to trees. In Asturias (NW Spain), where M. lusitanicus is considered a pest in several orchards, a faunistic-ecological study was carried out to describe the helminth community of this species and the main factors that could influence its helminth component species. For this purpose, our own collection of 710 voles from several orchards of various locations in Asturias was used. Eight helminth species, four cestodes and four nematodes, were found. Statistical non-parametric tests were used to analyse the effects of extrinsic and intrinsic factors on the diversity of the helminth community and species prevalence and abundance. The results show the influence of climate variables, the year and season of capture, as well as host age, on the diversity of the helminth community and the infection parameters of some helminth species, underlining the importance of their life cycles. In addition to shedding light on the helminth community of this rodent in Asturias, the results obtained could be used to improve the biological methods applied to fight the M. lusitanicus pest.

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 in 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 aboveground. For this reason, we developed a protocol that maximizes trapping success. This method requires the identification of active tunnel holes and the placement of traps directly in front of the exits. We also compared capture and recapture rates of Savi’s pine voles in three different trap types: Institut National de la Recherche Agronomique (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.