Genetic variability and conservation of the endangered Pannonian root vole in fragmented habitats of an agricultural landscape

Abstract

The distribution of the endangered glacial relict subspecies, the Pannonian root vole Alexandromys oeconomus mehelyi Éhik, 1928, is restricted to scattered localities in south-western Slovakia, which belong to the north-eastern zone of its range. Human-induced changes and fragmentation of the landscape have led to the gradual loss of suitable habitats and threaten its long-term survival. The study area in the Danubian Lowland is characterised by small habitat fragments and temporal fluctuations of the habitat area. Root voles were sampled at nine sites to study the level of genetic variability and structure of local subpopulations by scoring 13 microsatellite loci in 69 individuals. Genetic differentiation varied amongst local populations and we did not find a significant isolation-by-distance pattern. Bayesian clustering analysis suggested that dispersal effectively prevents marked genetic subdivision between studied habitat fragments. Significant pairwise differentiation between some subpopulations, however, may be the result of putatively suppressed gene flow. Low genetic diversity in the recent populations probably reflects the isolated location of the study area in the agricultural landscape, suggesting that long-term survival may not be assured. In order to maintain genetic diversity, it is essential to preserve (or even restore) habitats and ensure the possibility of gene flow; habitat protection is, therefore, recommended. Continuous assessment is necessary for effective conservation management and to predict the long-term survival chances of the Pannonian root vole in the study area.