The Population of the Common Grass Snake (Natrix Natrix Linnaeus, 1758, Colubridae, Reptilia) in the City of Moscow. 1. A History of Formation and the Features of Spatial Structure

The distribution, a history formation and the population dynamics of Natrix natrix in Moscow within the MKAD ring road have been studied. The features of distribution and the causes of abundance depression of the Common grass snake in the late 1990s to early 2000s are considered. The stages of the formation of the urban population over the past 30–40 years and the peculiarities of its spatial differentiation into separate micropopulations and groupings in the conditions of isolation and fragmentation under the anthropogenic impact are highlighted. Based on the cadastral map compiled of the current distribution of Natrix natrix in Moscow and the distribution of its locations, micropopulations and smaller groupings of the Common grass snake have been identified, forming the spatial and temporal structure of the population. The abundance of snakes and its possible dynamics in relatively isolated parts of the population is estimated. A potential of the micropopulations has been determined, and a forecast for the colonization of new territories by the Common grass snake given.