Genetic diversity in Siberian flying squirrel (Pteromys volans) in its western frontier with a focus on the Estonian population

Abstract

The Siberian flying squirrel population is experiencing a continuous decline in Estonia and Finland. Hence, the flying squirrel is listed in Annexes II and IV of the EU Habitat directive and is regarded as a priority species for protection by the European Community. So far, only a limited number of genetic studies have been conducted on this species—all using invasively collected tissue samples and most focusing on the Finnish population only. Our aim was to describe the genetic diversity of the Estonian flying squirrel population and its relatedness to the nearest populations from Finland and Karelia by using, for the first time, non-invasively collected faecal samples. Based on mitochondrial markers’ analysis, the Estonian population appeared more homogenous in comparison with the other two populations. Mitochondrial markers did not reveal essential genetic dissimilarities between Estonian, Finnish, and Karelian populations as they all shared the same mitochondrial haplotypes. Combined data from both mitochondrial and microsatellite markers indicated that the flying squirrel population in Estonia is genetically less diverse compared with the other populations. Finally, signs of inbreeding and heterozygote deficiency were detected in the Estonian flying squirrel population.