Estrous cycles and behavioural receptivity in social voles of the subgenus Sumeriomys (Rodentia, Arvicolinae)

Social voles of the subgenus Sumeriomys proved to be induced ovulators. Ovulation is induced only by actual copulation. Analysis of changes in vaginal epithelia in vole females has been performed. Stages of the estrous cycle in the species with induced ovulation are similar to those in the species with spontaneous ovulation. Behavioural receptivity of females correlates with a definite stage of the cycle, that is proestrus, the content of cornified cells in a smear being 30-70%. In laboratory seasonal variation of reproduction in social voles were recorded.