Seasonal variation of space use in Spermophilus fulvus (Sciuridae): insights from telemetry study

Investigation of animal spatial use is crucial for both fundamental understanding of life history and ecology of the species, and for addressing applied issues in population management and the conservation of threatened species. Acquiring precise data on movements remains technically challenging for mammals with specific lifestyles, particularly for secretive, burrowing, or subterranean taxa. Here, we present the first study of spatial use in Spermophilus fulvus (hereinafter – yellow ground squirrel), a large rodent exhibiting an extremely prolonged period of summer – winter hibernation. We collected data in March–August 2019–2023 in a wild population located in the Dyakovsky Forest National Park (Saratov Region, Russia). Movements of yellow ground squirrels were recorded using Global Positioning System tracking devices. Additionally, for the first time in a rodent hibernator, we have tested a method of attaching GPS-trackers to the skin using surgical glue, which proved to be completely safe for the animals, including those species that exhibit pronounced fluctuations in body mass during their annual cycles. During the mating season in spring, males travelled for long distances in search for estrous females, whereas females remained in the vicinity of their hibernacula. Males traversed several kilometres per day and made excursions well beyond the settlement boundary, visiting and mating with many females, employing a competitive mate‐searching strategy. The observed patterns of mating system are consistent with scramble competition polygyny involving promiscuity and multiple paternity in the yellow ground squirrel. Male movements were reduced on cold or rainy days, which imposed a risk of reproductive failure for females, which might remain unmated, if they came to estrus under unfavourable weather conditions. In summer, during the last weeks before hibernation, individuals of all sex‐age classes occupied relatively small home ranges. Due to the process of natal dispersal, young males covered greater daily distances than other individuals did; nevertheless, dispersal occurred over short distances: unlike males during the mating season, dispersing juveniles did not leave the boundaries of the settlement. The results demonstrate the restructuring of spatial use from the mating period through to hibernation in the yellow ground squirrel, and contribute to our understanding of population processes in ground squirrels.