INTERACTIONS OF CONTACT, ODOR CUES, AND ANDROGENS IN STRANGE-MALE INDUCED EARLY-PREGNANCY DISRUPTIONS IN MICE (MUS MUSCULUS)

Novel males can disrupt early pregnancy in female house mice (Mus musc ulus). In Experiment 1, exposure to novel males disrupted pregnancy, b ut exposure to male urine did not. In Experiment 2, urine from male or female mice or rats painted on females' noses did not influence pregn ancy. In Experiment 3, the conjunction of urine painted on female's no ses and vulval stimulation did not affect pregnancy more than water wi th similar stimulation. In Experiment 4, males housed above females we re separated from them by a wire mesh grid; intact males disrupted pre gnancy, but castrated ones did not. In Experiment 5, such housing of c astrated males or ovariectomized females produced a strong disruption of pregnancy if the stimulus animal was given testosterone but not if it was given oil injections. In Experiment 6, transfers of odorous emi ssions failed to disrupt pregnancy. Contact and androgen activity are necessary far strange males to disrupt pregnancy.