Some Aspects of the Population Ecology of the Common Shrew, Sorex araneus, near Oxford, England

Populations of the common shrew, Sorex araneus, reached a high of 2.8 individuals per acre in November 1965 and a low of 0.7 individuals in April 1966. The fall and winter population established well defined home ranges, but most of these were vacated at the onset of mating in the spring. Females established territories in autumn and maintained these at least until the first litters left the nest the following spring. Males established autumnal home ranges, but deserted these prior to the spring mating period, except in one case where a male established a spring territory encompassing the territories of several females. Infection by the larval nematode, Porrocaecum sp., and vagrant habits apparently had a significant bearing upon shrew density. A strong numerical response to a gradient of prey densities seems unlikely.