Responses of small mammals to the scent of animals that previously encountered traps

Responses of the common shrew (Sorex araneus), masked shrew (S. caecutiens), pygmy shrew (S. minutus), dusky shrew (S. isodon), and bank vole (Clethrionomys glareolus) to the scent of other species were studied in nature (Tver oblast) taking into account their species, sex, and age. The research was performed by comparing (criterion χ2, exact confidence interval for binomial distribution) the number of recipient individuals captured by traps with the scent of animals that previously contacted them and the number of animals that could be expected under the random distribution of captures. All responses of the animals to the scent unintentionally left by other individuals were regarded as manifestations of mediated olfactory communications. Positive responses (“the observed number of captures is greater than that expected”) absolutely prevail in the intraspecific relations within all the species and sex–age groups. They also play an important role in the interspecific relations, which is particularly noticeable in the yearlings of red-toothed shrews. The responses of these animals to the odor of bank voles vary from neutral to negative. It was shown that S. minutus avoids the scent of other species. Seasonal changes in the responses to the odor of different species and sex–age groups were considered.