Depression of the Population of the Steppe Polecat (Mustela eversmanii) in the Southern Urals

Long-term monitoring of the abundance of the steppe polecat (Mustela eversmanii) in Chelyabinsk oblast is considered. The analysis of the abundance dynamics of Mustelidae was carried out on the basis of monitoring data using the method of winter accounting (WA) conducted annually. Over the past few years, the steppe polecat has not been registered during accounting work in the mountain taiga; i.e., its numbers are either extremely low, or it has disappeared completely. In forest–steppe territories for 12 years, from 2008 to 2020, the abundance of polecats decreased almost 90 times, from 3058 to 34 individuals. The data on the number of the main prey species of the steppe polecat, two species of ground squirrels (Spermophilus major and Spermophilus pygmaeus) and the groundhog (Marmota bobak), are presented. The hypothesis of the possible influence of the American mink on the numbers of the steppe polecat is considered.