Diet of the European ground squirrel (Spermophilus citellus) in the southern Pannonian plain

Abstract

Overwinter survival of hibernators is directly influenced by the fat reserves accumulated during the active season. The European ground squirrel, Spermophilus citellus, an endangered flagship species of the open grasslands of central and southeastern Europe, is no exception. Considering anthropogenic changes affecting its habitats in northern Serbia, we studied the species’ feeding habits by subjecting its feces to microhistological examination. In addition to identifying plant remains in the feces, we examined the vegetation of the four study sites located inside a local mosaic of steppe and saline pastures. Our findings indicate that these remaining European ground-squirrel sites are diverse and stable grasslands covered by native flora that represents a complete dietary base for the species. The diet is dominated by a small number of plant species, specifically Achillea millefolium, legumes and grasses, with sporadic contributions from a number of other species. The diet of S. citellus also differs by location and season in that grasses dominate during the early season, while A. millefolium takes precedence later in the year. This dietary information is essential for the development of future species and habitat management strategies. In light of the predicted impact of climate change on grasslands in northern Serbia, our findings will be instrumental for translocations and conservation actions in the future.