Strand’s mouse Sicista strandi (Rodentia, Dipodoidea) on the southwestern periphery of its range: Genetic and environmental aspects

The position of the Sicista strandi population from the southwestern periphery of its range (the mountainous Caucasus, the vicinity of the Ekiptsoko cordon, Zol’sky district of Kabardino-Balkaria, the adjacent territory with terra typica of the species) in the species structure was investigated on the basis of a comparative analysis of the nucleotide sequences of a fragment of the gene of nu-clear DNA in this population and in representatives of the species from a number of localities from the Russian Plain for the first time. It was established that according to this molecular feature, the studied Caucasian population belongs to the southern grouping of the species, covering, in addition to the Caucasus, samples from the basins of the Lower (Rostov region) and Middle Don (Lugansk region) and presumably from the Lower Volga region, and differs from samples from the northern parts of the range in the Central Chernozem Zone (Kursk and Belgorod region). In the S. strandi population from the southwestern periphery of the range, a number of environmental and biological characteristics (biotopic confinement, population composition, abundance, diurnal, seasonal activity, reproduction, and nutrition) considered in a comparative aspect in connection with the genetic differentiation of the species were studied for the first time.