Small Mammal Communities in the Middle Ob Valley

Small mammal communities in different sections of the Middle Ob valley (floodplain and terrace) are considered based on an analysis of our own and published data. Small mammals were captured using similar methods everywhere: metal cones dug into ditches with pitfalls or placed along polyethylene film fences. We counted 16 517 animals of 21 species in the Middle Ob valley within the Khanty-Mansi Autonomous Okrug–Ugra during the period of 2004–2022. A total of 28–29 species of insectivores and rodents were recorded in southern taiga and middle taiga areas of the Middle Ob valley. The inexact number of animal species is due to the fact that the classification of voles of the arvalis group in the studied area has not been completely determined. The given descriptions of all the revealed species include the occurrence, abundance, and other aspects of small mammal ecology. The specific features of the southern taiga and the middle taiga sections of the Middle Ob valley, as well as of the floodplain and terrace in general, are revealed. The common hamster, narrow-headed vole (southern subspecies), Korean field mouse, and herb wood mouse occur only in the southern taiga section of the Middle Ob valley and are not common in the middle taiga section of the studied area. These species also avoid floodplain biotopes. The determined list of dominants includes the common shrew and the root vole for the floodplain and the common shrew and the northern red-backed vole for the terrace. The codominant species are represented by the Eurasian pygmy shrew and Laxmann’s shrew, as well as by the harvest mouse. The valley of the Middle Ob is dominated by western Palearctic species. They tend to dominate both the floodplain and the terrace.