Influence of sexual experience and social environment on fertility and incidence of mating in young female bank voles (Clethrionomys glareolus).

Between 30 and 40 days of age, female bank voles were kept singly, in female pairs, separated from an adult male by a wire mesh, or paired with a vasectomized male. At Day 40 they were paired with adult intact males. Fertility at the first mating was low (22-25%), but if the females had previously mated with the vasectomized male fertility of the subsequent mating with the intact male was significantly increased (63%). Sterile matings therefore had a priming effect on the females, and could be important for the development of puberty in wild females. Only 55-59% of the females without contact with males between Days 30 and 40 mated with the fertile male. Contact with a male through a wire mesh increased the proportion to 80% and co-habitation with a vasectomized male to 94%. In the last group, mating also occurred at a younger age.