Ecology of the European water vole (Arvicola terrestris L.): a case study of the middle Lena river

The article presents the materials of studying Arvicola terrestris on the territory of the middle Lena River, where human activity aimed at enriching the commercial species contributed to the development of new interspecific relations after the acclimatization of Ondatra zibethica. The populations of these species in interaction with each other and with the environment transformed by humans are a dynamic natural system, in light of this the study of relationships and patterns in this system is of particular scientific interest. The modern fauna of semiaquatic rodents of Central Yakutia was formed after the 1940s as a result of Ondatra zibethica acclimatization. The native species that inhabit the river and procure food in the adjacent biotopes are Arvicola terrestris and Microtus oeconomus, which by their nature and attachment to the water body are amongst the inhabitants adapted to the near-water existence like the introduced muskrat. All of these species are potential competitors to each other. However, the muskrat as a larger and more aggressive species can intensively put out other species from these stations. Previously numerous species of Arvicola terrestris has been declining in its traditional habitats since the beginning of the 1980s. Consideration of the geographic and statistical distribution of these animals makes it possible to assess with concrete examples the state and stability of of the population dynamics of this species. The muskrat as a rodent with more active ecological position and a territorial species (family plots), surpassing its counterpart in size and aggressiveness, apparently displaced it from its habitats. M. Ya. Marvin [1959] previously published the relatable materials after the acclimatization of muskrat in Karelia. As a result of comparing the habitat data and a comprehensive analysis of the ecology of the European water vole, we can assume the development of new biocenotic relationships between the European water vole and the acclimatized muskrat in the form of competition for food and territory in the biogeocenoses of Central Yakutia.