The researches realised on 60 females evidentiated the fact that the way they were used could have an influence on the reproduction activity on the females. The experiment lasted for eight months (from April to November) and we used six different variants of female presentation to the male (V1 in the second day post-partum; V2 in the third day; V3 in the seventh day; V4 in the tenth day; V5 in the fourteenth day; V6 in the twentieth day). The obtained results demonstrate that in the case of natural fecundating, V1 (female presentation of the male in the second day post-partum) is preferable. Through the fecundity didn't outrun 41.17 per cent and the prolificity 6.1 cub/female, female receptivity in this variant was the best 38.63 per cent. We might believe that rhythm imposed by V1 care bad in time to female exhaustion. However there were no elimination through reform or death in this group during the entire experimental period.