Number and Distribution of the Narrow-Headed Vole Lasiopodomys gregalis (Pallas, 1779) (Cricetidae, Rodentia) in Western Siberia

—According to the data collected in the second half of summer for the period from 1954 to 2016 in the plain and mountainous parts of Western Siberia, the distribution and number of the narrow-headed vole in the zonal and provincial aspects were analyzed. Based on cluster analysis of the matrix of similarity coefficients of abundance indicators obtained by averaging the initial data by years and groups of geobotanical maps units, classification of habitats according to the degree of favorable environmental conditions for the vole is made. The averaged samples are divided into five types of favorability: from the optimal type, where the abundance of the species is highest in the whole area studied, to the extreme type, where it is not found. In the southern part of the West Siberian Plain, the narrow-headed vole prefers steppes, and in the subarctic tundra, it prefers communities of river valleys. In the Altai and Kuznetsk-Salair mountain regions, it is most common in the subalpine light forests, tundra, and tundra–steppes of northwestern and southeastern Altai. On average, this vole prefers open habitats in Western Siberia. According to the classification and the structural graph, the dependence of the vole abundance on a number of factors and their inseparable combinations (environmental and anthropogenic regimes) was revealed. The greatest relationship with its distribution in the habitats of Western Siberia is traced to heat and water availability. On the plain, the number of this vole increases from the middle taiga, where it was found only once, to the subzone of the subarctic tundra in the north and to the forest–steppe and steppe zones in the south. In the mountains it is most abundant in Southeastern Altai, where there is a relatively high proportion of the habitats that are most favorable for the narrow-headed vole.