Биофаунистические заметки по млекопитающим южных отрогов хребта Черского (Магаданская область)

Data on the species composition of theriofauna in the mountain-lake district of the Cherskiу Range southern spurs are given. New data on habitats, relative abundance, and some population characteristics of mass species of small mammals are also reported. The basins of Lake Momontay and Lake Urultun, located at 1048 and 944 m above the sea level and belonging to the basin of the Omulyovka River upper reaches, were inspected in August 2021. Small mammals were caught using the standard trap-line and cone methods. A total of 650 trap-days and 80 cone-days were worked out; 260 animals were caught. The species composition of large and medium-size mammals was identified by traces of their life activity and by visual contacts during route surveys of the total area about 350 km2. The routes made 50 km of length. 18 species of mammals referring to 16 genera, 9 families, and 5 orders were found to inhabit the area; they prevalently belong to the most numerous and elements of the theriofauna, widespread in the North-East of Siberia boreal Holarctic (Clethrionomys rutilus, Alexandromys oeconomus, Ursus arctos, Rangifer tarandus, Alces alces) and ancient taiga Palearctic (Sorex caecutiens, S. isodon, Myopus schisticolor, Craseomys rufocanus, Martes zibellina). A new habitat (the northwestern coast of Lake Momontai) was identified for the North Siberian vole (Alexandromys hyperboreus). Besides, the findings of the equal-toothed shrew (Sorex isodon) in the study area expand its distribution borders 160-180 km to the north of the Upper Kolyma basin.