Communities of small mammals on the left bank of the Middle Ob

The purposeful studies of communities of small mammals (insectivores and rodents) on the left bank of the middle Ob within the Khanty-Mansi Autonomous Okrug – Ugra (Khanty-Mansiysk, Nefteyugansk, Surgut and Nizhnevartovsk districts) were carried out for the fi rst time from 2011 to 2020. Animal counts were carried out both in transformed and specially protected natural areas. The purpose of the work is to compare the geographical distribution of small mammals on the left bank of the middle Ob and assess their signifi cance (based on shared participation in the total abundance) in the communities of this group of animals. The methods of ditch with pitfalls and catching fences from polyethylene fi lm were used to catch insectivores and rodents. The studies made it possible to relatively fully identify the species composition of small mammals (18 species). In general, the common shrew, the northern red-backed vole and the root vole dominate on the left bank of the middle Ob. During the studies rare species and features of their stay in this territory were found such as: the Altai mole, the Eurasian least shrew and the taiga shrew, the Siberian large-toothed shrew, the wood lemming the fi eld vole. The study established that the number of water voles after the mass reproduction in 2013 and in the next years from 2014 to 2020 in Ugra is characterized by low indicators. Their role in maintaining the natural focus of tularemia of the fl oodplain-river type in Ugra during these years is negligible. In general, communities of small mammals on the left bank of the middle Ob are relatively similar, which was determined by the collection of selected large units – a complex of fl oodplain, forest and bog biotopes.