Abstract <p>Interspecific interactions within small-mammal communities can modify species-specific population characteristics depending on overall community state. Using a 21-year mark–recapture dataset from the forests of the Northern Urals, we examined how population density influences non-resident activity in three abundant species: red vole (<i>Clethrionomys rutilus</i> Pallas), common shrew (<i>Sorex araneus</i> L.), and Laxmann’s shrew (<i>Sorex caecutiens</i> Laxmann). We found a significant positive effect of heterospecific density on the number of moving (non-resident) individuals. Red vole, the dominant species in the community, exerted the strongest influence: its density significantly influenced non-resident activity both within its own species and in the two shrew species. In red voles, non-resident activity was primarily driven by total rodent density, with an additional significant effect of shrew density. In contrast, in both shrew species, total shrew density had the strongest effect, although rodent density was also significant. Non-resident activity was influenced not only by the density of resident populations but also by the density of moving (non-resident) individuals. Models incorporating non-resident density provided the best fit to the data. We suggest that at high population densities, the frequency of social contacts—including interspecific interactions—increases, thereby promoting movement.</p>