Small mammals of the middle course of the Pechorskaya Pizhma river: community structure and population dynamics

Abstract

Here, we present the results of research on the community structure of small mammals and the population dynamics of their number in the northern taiga of the Komi Republic in the basin of the middle course of the Pechorskaya Pizhma River (64°53¢ N, 51°28¢ E). Animal counts were carried out in the second half of August (2014–2020) with fishing grooves and covered different habitats. The grooves with a length of 50 m and 5 cones within it were opened in the second half of the summer for 10 days. A total of 280 groovedays were worked, 1157 individuals of 14 species were caught. Three species: Sorex caecutiens (28.1 %), S. araneus (25.6 %), and Myodes rutilus (14.7 %) dominated in the community structure of Micromammalia. The proportion of species varies in different habitats and depends on the structure of the vegetation of the lower layers. In biotopes with moss cover, the share of three dominant species exceeds 85.0 %. In grassy habitats, it decreases to 49 %. There is a significant proportion of Myodes glareolus, Alexandromys economus, Could agrestis and Sicista betulina, which is 43.2 %, while in taiga habitats there are less than 7 %. The total number of small mammals varied from 12.1 to 70.6 ind. per 10 groove-days. In the years of depressions, 5–6 species were caught, while the number of species increased to 12 species during the years of peak abundance. Interspecific synchronicity in the dynamics of the number of animals is more pronounced in shrews than in voles.