Siberian weasel Mustela sibirica Pallas, 1773 predatism on bats during winter period

This work presents the results of a three-year natural environment experiment in a cave in Barsukovskaya, Siberia), aimed at assessing the possible impact of mammals preying on a wintering group of bats. The average consumed biomass amount per year was about 2108 g and the estimated number of prey animals was 214, which is about 20% of the maximum number of animals observed. The biomass consumed poorly correlates with the number of animals in the cave. The proportion of the various species remaining in the excrement of predators is strongly determined by the number of these species in the accessible part of the cave. The amount of excrement indicates the regular predatism on bats and, therefore, the presence of specific behavioural adaptation in Mustela sibirica.