DISTRIBUTION AND GEOGRAPHIC LIMITS OF THE ALTERNATIVE CYTOTYPES OF TWO MICROTUS VOLES IN EUROPEAN RUSSIA

Abstract

Chromosome data on the distributional limits of Microtus voles (M. subterraneus, M. arvalis) in the very east of Europe are presented. Wide border space reported formerly between the two subterraneus cytotypes (2n=54, 2n=52) as well as between the common vole cytotypes (arvalis and obscurus, both 2n=46) have been narrowed with the study progress, especially in the case of the common vole. For the first time, hybrid karyotypes were observed in a local sample, providing evidence of natural hybridization in the arvalis - obscurus contact zone.