THE CURRENT STATE OF SPECKLED GROUND SQUIRREL (SPERMOPHILUS SUSLICUS GULD.) POPULATIONS IN THE VOLGA REGION: HISTORY AND SCALE OF EXTINCTION
Authors:   Penza State University, Titov S.V. , Kartavov N.A. ,   Penza State University, Leonova N.A. ,   Penza State University, Smirnov D.G. ,   Penza State University, Chernyshova O.V. ,   Penza State University, Kuzmin A.A. ,   Penza State Technological University
Published: February 2025

As a result of large-scale anthropogenic transformation of landscapes as a result of human economic activity and population depression, the range of the speckled ground squirrel has experienced severe fragmentation by the beginning of the 21st century. Almost in all geographically isolated populations of the speckled ground squirrel there is a strong reduction in the number of colonies. This situation was the reason for the inclusion of Spermophilus suslicus in the international, state and regional Red Data Books with the status of a species threatened with extinction. The aim of this work was to analyse the current state of S. suslicus colonies in the Volga region, as well as to investigate the history, extent and reasons for the extinction of this species in steppe and forest-steppe areas of the region. The material for the work was the data of monitoring studies of colonies of the speckled ground squirrel in the Right-Bank Volga region, namely in the territories of Penza, Saratov, Samara, Tambov, Ulyanovsk regions, the Republics of Mordovia and Tatarstan and the Chuvash Republic, conducted in the period from 2000 to 2024. During the study of the detected colonies, the biotopes of their localization were described with visual or capture counts of the density of individuals (ind. per ha) in the populations. Over 24 years of observations in the right-bank Volga region, a sharp decrease in the number of S. suslicus colonies was observed. From 2000 to 2012 it decreased by 68,6 %, and from 2012 to 2024 – by 53,1 %. In total, 87 (85 %) colonies of the speckled ground squirrel have ceased to exist. The most frequently recorded biotope element of S. suslicus habitat across all study time points (2000–2012–2024) was grasslands and pastures at 80, 53, and 53 %, respectively. The second most frequently recorded element in 2000 and 2012 was floodplain meadow areas (40 and 41 %, respectively). In 2024 they were replaced by drier steppe flat areas at 40 %. The third biotope element of speckled ground squirrel habitat was different at all time points of the study: in 2000 – steppe fallow and unimproved areas, 25 %; in 2012 – dry steppe flat areas, 41 %; in 2024 – steppe slopes, 33 %. The main biotopical features of habitats that contribute to long-term existence and preservation of speckled ground squirrel’s colonies under increasing depression in numbers were identified. These are low grass and average level of projective vegetation coverage as protective properties of the biotope, as well as dense turf and deep groundwater table as necessary conditions for burrow construction. Necessary requirements for habitats in which speckled ground squirrel restoration activities are expected to be carried out are related to increasing the protective properties of the biotope. The most important of them are microstatial richness of the habitat (multiple transitions) and direct human presence.