Hormonal regulation of aggression toward juveniles in female house mice

Adult female house mice that had been living in groups inflicted more wounds upon juvenile opponents than did females that had been housed in isolation. Ovariectomy blocked this enhancement of aggression by grouping. Aggression in ovariectomized females was augmented by treatment with testosterone propionate, but not by treatment with estradiol benzoate or progesterone. Preputial gland size was greater in group-housed females than in isolates; this difference was abolished by ovariectomy. Testosterone proprionate, but not estradiol benzoate or progesterone stimulated preputial gland growth in ovariectomized mice. These results are interpreted as supporting the hypothesis that the groupinginduced enhancement of juvenile-directed aggression in female mice is mediated by an increased secretion of ovarian androgens.