Copulatory behavior supports a new insight into taxonomic status of root vole Alexandromys oeconomus (Rodentia, Arvicolinae)

The aim of the study was to evaluate the phylogeny and relationships of the root vole Alexandromys oeconomus with the other species of the tribe Microtini, using the comparison of the characteristics of sexual behavior. Thirteen copulatory behavior patterns that form a specific stereotype of the species’ mating behavior are used. The results showed the multiple thrusting stereotype of copulation, which includes separate intromissions and a very first mount with intromission, is ending with ejaculation (from 10% to 48%, depending by the investigated population). The number of ejaculations is comparatively big, varying from 4 to 7 (an average of 4.6) and the genital stimulation rate is from 68 to 260 thrusts. The males of the root vole noted active courtship for the female, which is accompanied by singing, waltzing and marking of the substrate. Marking the territory is manifested by rubbing the femoral region on the substrate, in which the secretion of the hip glands is applied to it. Analysis of the distances (or similarities) between species according to patterns of sexual behavior using the method of cluster analysis indicates the proximity of A. oeconomus to species of the genus Alexandromys and a considerable distance from representatives of the genus Microtus (Microtus s.str. and Sumeriomys). Significant interpopulation differences in copulatory behavior of the Central Asian phylogroup are established (54% of all the behavioral traits studied). The transformation of the stereotype of mating in individuals from Beringia phylogroup in comparison with the Central Asian one is particularly significant and reaches 77% of all the behavioral traits. The data obtained by the analysis of the copulatory behavior of the Alexandromys oeconomus support the separation of the species from genus Microtus. How to cite this article: Zorenko T.A., Atanasov N.A. 2018. Copulatory behavior supports a new insight into taxonomic status of root vole Alexandromys oeconomus (Rodentia, Arvicolinae) // Russian J. Theriol. Vol.17. No.1. P.48–57. doi: 10.15298/rusjtheriol.17.1.05