Factors that affect long-distance movements of small rodents and shrews in the Ural taiga: disentangling dispersal from excursion movements.

This article investigates the factors influencing long-distance movements (LDMs)—defined as movements beyond the typical home range—of mouse-sized rodents and shrews in the Ural taiga, Russia. Using capture–marking–recapture (CMR) and group marking with biomarkers (tetracycline and rhodamine B), the study identified 89 individuals from six species moving distances of 250 to 500 meters, with most movements classified as excursions rather than dispersal events. The analysis revealed that species identity and population abundance significantly affected LDM occurrence, while sex, maturity, and additional food supply did not, suggesting these movements serve exploratory purposes. Biomarker group marking proved more effective than CMR in detecting LDMs, and the study provides the first excursion data for Sylvaemus uralensis, Microtus arvalis, and Sorex caecutiens, with the maximum known excursion distance recorded for Myodes glareolus.