Study of the ecology of the Eurasian pygmy shrew ( L.) in the European part of the range. note III. Ecologica population structure, moulting, numbers of the population and its variety

Summary of the analysis of the population ecological characteristics of the the eurasian pygmy shrew in the European part of its range, that include results of ecological structure of the population, molting and population dynamics of the shrew. The ecological structure of the population is characterized by a faster increase in juveniles, which amount reaches more than 72% in September. Every year the age structure of the population changes, which correlates to the intensity of reproduction and the total amound individuals in population. The sex ratio depends on the age of the individuals, the season of the year and the condition of the population. As compared to the numbers of the siberian population, we established a relatively low density of population in the study area (0,3 ind. per 100 trap-nights or 2,2 ind. per 10 ditch-days). The number changes noticeably from year to year, but without any sharp periodicity and is general it is not synchronous with the dominant species - . Nevertheless, over more than 60 years of studies of population of , only four unclear rises emerged. These increases in numbers occur under the influence of a rather complex combination of an exogenous factors.