Evaluation of methods to estimate field vole Microtus agrestis abundance in upland habitats.

Abstract

Field vole abundance was assessed on a range of upland habitats in spring and autumn, using live-trapping, snap-trapping and vole sign index methods. Three estimates of vole numbers were derived from live-trapping, five from snap-trapping and one from vole signs. Estimates were compared using a correlation matrix in order to establish the most accurate and consistent method. Snap-trapping for five nights provided enough information to calculate vole density, though the method was time consuming. Vole abundance indices derived from two nights' snap-trapping were significantly correlated with indices from five nights' trapping. Live-trapping and vole sign index were discounted as methods for this study area, as both proved unreliable.