The effects of differential prenatal and postnatal social enviroments on sexual maturation of young prairie deermice (Peromyscus maniculatus bairdii).

We compared the influence of different social enviroments on sexual maturation of young prairie deermice. Between 12 and 48 hr after parturition, one-half of a litter from a population was exchanged with one-half of a litter from a bisexual pair. In each situation the remaining half-litter served as controls for the exchange procedure. The testes and vesicular weights of population-reared males were significantly larger than those of males reared by bisexual pairs, irrespective of prenatal enviroment. Generally, population-reared females also had larger reproductive organs than those reared by bisexual pairs, although these differences were not statistically significant. There were no significant differences in the adrenal weights of males or females, but females reared by bisexual pairs had larger absolute and relative adrenals than females reared in populations.