Genetic diversity of bat species in the cross-border area of Greece and Bulgaria

Bats form a diverse order of mammals with a crucial ecological role. Bat populations appear to be declining because of human-induced environmental stress. Genetic methods can contribute to detailed investigations of species diversity and assessments of population status. Here, we aimed to study the genetic diversity of bats across the Rhodope Moun-tain Range, where species with a large distribution as well as rare species with a limited distribution are found. Bat sam-ples were collected and morphologically identified within the catchment area of Nestos (Mesta) River and from caves in the region of Momchilgrad - Komotini. Based on the analysis of a mitochondrial COI gene region of 650 bp length, the samples were classified in 9 distinct genera and 21 species, an important part of Balkan bat species diversity. Min-iopterus schreibersii displayed the highest number of haplotypes and Rhinolophus hipposideros the highest mtDNA di-versity levels. The majority of the samples were grouped with other European sequences and no specific geographic distribution of haplotypes was observed, except for Barbastella barbastellus and Hypsugo savii, where a western/eastern divide is apparent. Three species with the highest number of samples were further analyzed using 4-5 microsatellite markers per species. No sign of population differentiation was found between studied samples for these three species and moderate to high diversity levels were detected for Rhinolophus blasii and Rhinolophus euryale, in contrast to mito-chondrial analysis. The results confirm the presence of specific bat species in the cross-border area of Greece and Bulgaria through genetic identification and provide information for levels of genetic variation for some of them that may con-tribute to future bat management efforts in the region.