Assessment of the effect of contemporary climate warming on the small ground squirrel fleas population dynamics in Northwestern region of Caspian Depression

Abstract

The dominant zonal rodent species in the steppes and semi-deserts of the Caspian Lowland is the small ground squirrel Spermophilus pygmaeus (Pallas, 1778). Flea species, which are its specific ectoparasites, play a significant role in the occurrence of plague epizootics in this area. The impact of global climate warming on the population dynamics of the fleas of the small ground squirrel in the northern deserts on the territory of the Caspian Lowland is discussed in this article. The literature sources and extensive archival materials were used for the analysis. The Ilmen-Pridelta landscape region (southwest of the Astrakhan Region), which is most fully characterized through the necessary quantitative indicators, was chosen as a model territory. The data of the annual spring-summer registration of indices of the flea abundance in wool and at the entrances of the burrows of the small ground squirrel, as well as his abundance rates (number of specimens per 1 ha), average monthly air temperature values reported by meteorological stations in Astrakhan over the past 70 years were statistically processed. The article reveals the mechanism of the influence of contemporary climate warming on the dynamics of the number of fleas of the small ground squirrel in the territory of the Caspian Lowland over the period of 1950-2021.