A preliminary investigation into whether grazing marsh is an effective refuge for water voles from predation
The water vole (Arvicola amphibius) has suffered a massive and rapid decline in the UK recently, due to habitat fragmentation and predation by American mink (Neovison vison). The spatial configuration of the habitat can mitigate the effects of predation on water vole colonies. In reed bed, mink predation rate declines with distance to a main channel. Over-winter mortality of water voles was monitored at an extensive grazing marsh site where mink were present to determine if this habitat provides a similar refuge from predation. Water vole mortality (74% by predation of which 71% by small mustelids) was significantly correlated with channel width and negatively correlated with distance to nearest scrub, suggesting that extensive grazing marsh can provide water vole with some refuge from predation.