Population genetic structure of the Mediterranean horseshoe bat Rhinolophus euryale in the central Balkans

Abstract

Migratory behaviour, sociality and roost selection have a great impact on the population structure of one species. Many bat species live in groups, and movements between summer and hibernation sites are common in temperate bats. The Mediterranean horseshoe bat Rhinolophus euryale is a cave-dwelling species that exhibits roost philopatry and undertakes seasonal movements which are usually shorter than 50 km. Its distribution in Serbia is restricted to karstic areas in western and eastern parts of the country, with a lack of known roosts between them. In this study, microsatellite markers were used to evaluate genetic variation in this species in the Central Balkans. Specifically, spatial genetic structuring between geographic regions and relatedness within different colony types were assessed. All analysed loci were polymorphic, and there was no significant inbreeding coefficient recorded. A moderate degree of genetic differentiation among the sampled colonies was found, and significant isolation by distance was recorded. Our results revealed that populations show a tendency to segregate into three clusters. Unexpectedly, populations from Montenegro and Eastern Serbia tended to group into one cluster, while populations from Western Serbia and Slovenia represented second and third cluster, respectively. The majority of variance was partitioned within colonies, and only a small but significant portion among clusters. Average relatedness within colony members was close to zero, did not differ significantly between the different colony types, and kinship is unlikely to be a major grouping mechanism in this species.

Integrating population genetics to define conservation units from the core to the edge ofRhinolophus ferrumequinumwestern range

“…Our study revealed high and homogeneous levels of genetic diversity within the European mainland colonies examined. These levels were similar to those previously detected in colonies from the eastern parts of R. ferrumequinum distribution (Rossiter et al, 2007; Rossiter et al, 2000), or in other bat species such as Rhinolophus euryale and Myotis myotis (Budinski et al, 2019; Castella, Ruedi, & Excoffier, 2001). We did not find evidence of departure from Hardy-Weinberg equilibrium within colonies or when considering the European mainland colonies altogether.…”

Integrating population genetics to define conservation units from the core to the edge of Rhinolophus ferrumequinum western range

“…These levels were similar to those previously detected in colonies from the eastern part of R. ferrumequinum distribution (Rossiter et al, 2007(Rossiter et al, , 2000, or in other bat species such as Rhinolophus euryale and Myotis myotis (Budinski et al, 2019;Castella, Ruedi, & Excoffier, 2001). We did not find evidence of departure from Hardy-Weinberg equilibrium within colonies or when considering the western French and Spanish Basque colonies altogether.…”

Mitochondrial phylogeography of the Mediterranean horseshoe bat on the Balkan Peninsula

“…Only two haplotypes have been recorded in Montenegro, and both are also present in Italy and eastern Serbia. Genetic similarity between R. euryale populations in eastern Serbia and Montenegro has also been reported based on nuclear microsatellite data [25]. Within clade III, H58 from the eastern Mediterranean area is evidently different from the other haplotypes in this lineage, and it is possible that they evolved in different glacial refugia.…”

“…The star-like topology of median-joining tree, mismatch distribution and shallow genetic differentiation in R. euryale point to a relatively recent and rapid population expansion, while the high genetic diversity supports the hypothesis that the Balkan region was the most likely refugium for the clade III of R. euryale during the Late Pleistocene. Balkan populations of the Mediterranean horseshoe bat harbor relatively high levels of genetic diversity, at both the nuclear [25] and mitochondrial levels. These populations have been recognized as the most stable and the most numerous in Europe [21], and since they carry a substantial part of the species' genetic variation, their protection is of great importance.…”

“…The first genetic study of this species on the Balkan Peninsula was carried out recently using nuclear microsatellites [25], and to the best of our knowledge, there are no published data on mitochondrial diversity in R. euryale from this region. We conducted extensive sampling of R. euryale colonies in Serbia and neighboring countries and analyzed D-loop sequences of mitochondrial DNA in order to compare results with previously published data.…”