Daily and Seasonal Activity Patterns of the Endemic Balkan Snow Vole (Dinaromys bogdanovi) Within a Sympatric Small Mammal Community

Understanding the temporal ecology of endemic species is important for conservation planning in biodiversity hotspots during global climate change and habitat alteration. We used three years of camera-trap monitoring across two deployment periods to quantify daily and seasonal activity patterns of the endemic Balkan snow vole (Dinaromys bogdanovi) and sympatric terrestrial small mammals in Biokovo Nature Park, Croatia, within the Western Balkan glacial refugia. Dinaromys bogdanovi was predominantly nocturnal, with minor but consistent diurnal activity, and shifted from multimodal nocturnal activity in spring, summer and autumn to a unimodal winter peak. Temporal niche differentiation occurred between D. bogdanovi and the sympatric small mammals during some seasons. These differences were associated with nocturnal peak timing and the greater diurnal activity of D. bogdanovi. In summer, the detected taxa showed greater overlap in predominantly nocturnal activity, consistent with a possible influence of thermal conditions on surface activity, although temperature was not measured. We also provide quantitative activity data for the geographically isolated Dinaric population of Eliomys quercinus. This study demonstrates the value of long-term camera trapping for monitoring cryptic small mammals and provides a baseline for evaluating future changes in activity, habitat use and community interactions, supporting conservation planning for endemic species facing climate change and anthropogenic pressures.