Diagnostic Criteria for Identification of Microtus s. l. Species (Rodentia, Arvicolidae) of the Ukrainian Carpathians

Abstract

The present paper deals with the issues of diagnostics of morphologically similar vole species (Microtus s. l.) common in the fauna of the Ukrainian Carpathians. Three groups of characters have been analysed: external traits (linear body dimensions, coloration features, etc.), morphological and anatomical features of the skull (size of its structures, form of certain bones and sutures, etc.), and morphology of molar teeth (number and form of enamel lobes and triangles). The analysis of museum specimens of voles collected in the region of the Ukrainian Carpathians has shown that external and cranial non-metric characters allow reliable identification to genus level, while for species diagnostics it is necessary to use a complex of characters including structural features of molars and dimensions of skull structures. The height and width of the braincase have the largest diagnostic value among cranial characters for the sibling species complex Terricola subterraneus-Terricola tatricus, while for the pair of morphologically similar species Microtus agrestis-Microtus arvalis such value have the upper molars length, condylobasal length, and braincase height. The most significant, revised and newly described, diagnostic characters have been generalized into an identification key, especially convenient for use during work with collection materials.