INTRASPECIFIC VARIATION IN THE INDUCTION OF FEMALE SEXUAL RECEPTIVITYIN PRAIRIE VOLES

Prairie voles (Microtus ochrogaster) are monogamous New World rodents which show geographic variation in social behavior. In this study, par ameters of female reproduction which might be related to mating system were compared in prairie voles from eastern Kansas (KAN) versus centr al Illinois (ILL). KAN females showed a more rapid onset of natural es trus following exposure to a male and were more likely to respond to i njections of a low dose (0.5 mu g) of exogenous estradiol benzoate tha n ILL females. Neither mating duration nor pregnancy success-after mat e removal differed in KAN versus ILL females. These results suggest th at ILL voles are less sensitive than KAN voles to the estrus-inducing effects of either endogenous or exogenous estrogen, supporting the hyp othesis that variations in reproductive strategy occur among geographi cally discrete populations of prairie voles. (C) 1998 Elsevier Science Inc.