Predation on Voles: An Experimental Approach

Abstract

We manipulated access to penned populations of voles to assess the relative importance of four different groups of predators in eastcentral Illinois. Larger carnivores (feral cats, raccoons, and foxes) generally accounted for more losses than did the other groups, particularly in winter. Losses to small carnivores (weasels) and raptors peaked in autumn, but snakes had low impact throughout the year (none at all in winter when they were not active). Large carnivores and snakes showed no consistent preference for young or adult voles of either sex, whereas small carnivores and raptors regularly took more immature voles of both sexes. The heavy use of voles by large carnivores, even when densities of voles in surrounding fields were low, supported the hypothesis that resident generalist predators can respond quickly to local increases in density of voles and may prolong periods of low densities.