Breeding and Population Structure of the Root Vole Alexandromys oeconomus Pallas, 1776 (Cricetidae, Rodentia) in the Southern Trans-Ural Region

—Features of the breeding and population structure of the root vole inhabiting the Southern Trans-Ural region during the periods of 1981–2001 and 2020–2022 are considered. Animals were captured during both winter and snowless periods. A total of 754 root voles were captured using ditches with pitfalls (guide fences made of polyethylene film) and trap lines. As in the other parts of their range, root voles in the Southern Trans-Ural region prefer near-water habitats. Winter breeding is characteristic of this rodent in the Southern Trans-Ural region, but the most intensive breeding is observed in May–June. These months are also characterized by the maximum fecundity for both overwintered and young females. Overwintered females can produce up to four litters during their reproductive period, while young females can produce 3–4 litters. The fecundity of overwintered females is statistically significantly higher than that of young ones. In the months February–May, overwintered animals dominate in the root vole population, while in June and the following summer and autumn months, underyearlings predominate. Males dominate among the overwintered and underyearling animals; at the end of summer and in the autumn, the sex ratio among these age groups of root voles levels off.