Morphogenetic Effects of Drought and Nonselective Elimination in Population of Bank Vole (Clethrionomys glareolus) in Southern Taiga Subzone

Abstract

Methods of geometric morphometrics have been used to estimate the influence ratio of nonselective elimination and drought factors on variation in the shape and size of the mandible in the population of bank vole (Clethrionomys glareolus Schreb.) in the southern taiga subzone. Nonselective elimination of rodent populations for medical and sanitary purposes was carried out in a felling site located in a focus of hemorrhagic fever, in the spring of a climatically normal year and of a dry year. The summer samples of mature young of the year from control bank vole colonies and impact colonies (i.e., recovered after deratization) in adjacent years have been compared. The results show that drought, nonselective elimination, and the interaction of these factors have significant effects on the size and shape of the mandible. Changes in its shape under drought conditions are largely due to allometry. Morphogenetic effects of nonselective elimination are highly repeatable between climatically different years. A significantly higher level of within-group morphological disparity (MNND) of the undisturbed control cenopopulation in a dry year has been revealed, which indirectly indicates a stronger destabilization of morphogenesis upon exposure to the autecological factor. Every ecological factor contributes to the development of specific configurations of the mandible; i.e., it induces certain changes in morphogenesis in response to aut- and synecological effects and their combination.