Сучасний стан популяції бабака степового (Marmota bobak) у Стрільцівському степу (схід України)

Abstract

The Striltsivskyi Steppe Nature Reserve (with a total area of 522 hectares) was created in 1948 to preserve the steppe marmot population; however, according to the population state studies carried out in the course of the reserve operation, a decrease in the marmot population has been established. This article is aimed to provide current data related to the marmot population monitoring results. The author established the number of colonies as well as adult and this year’s individuals inhabiting the nature reserve territory in 2020. The author explored the structure of each colony’s site and studied their area, shape and number of permanent and temporary burrows to analyze the state of the population. Only a quarter of all colony sites located in the territory of the reserve can be characterized as permanent ones. According to the author, despite a slight increase in the number of colony sites in the northern part of the Kreydyanyi Ravine and slopes towards the Cherepakha River, the entire population tends to decline. A high level of age structure misbalance and pronounced population fragmentation are observed, which are more evident in the left-hand slope in the northern part of the Kreydyanyi Ravine and in the vicinity of the Zapovidna Balka, which characterizes the population state as unstable. Changes in the vegetation cover are the principal reasons for these processes: increased area occupied by bushes, high grass stand, dry grass residues and predators (foxes and domesticated dogs). It is possible to forecast that the number of steppe marmot will continue to fall due to the current state of the vegetation cover state and absence of large grazers. The state of colony sites improves in the territories of with cattle grazing and haymaking. The state of colony sites and number of individuals in the colonies improved to a certain degree in the slopes towards the Cherepakha River where cattle grazing was carried out. As many as four colonies were found there in 2018 while their number reached ten in 2020. Exclusively reserve status under the current steppe conditions without large grazers will fail to improve the marmot population. The author suggests carrying out such actions aimed to prevent the decrease in the number of marmot population in the nature reserve territory as introducing cattle grazing, haymaking in the territories of colony sites, removing high grass near permanent burrows and conducting ecology awareness-building campaigns among the local population to prevent illegal hunting.