CHEMICAL CUES FROM FAMILIES DELAY PUBERTY IN MALE CALIFORNIA VOLES

The role of chemical cues in the delay of puberty in male California voles (M. californicus) was investigated. Males that were raised from weaning in bedding from their families were delayed in attainment of adult androgen levels and seminal vesicle weights compared to males raised in clean bedding. In a 2nd experiment, the source of the suppressive cues was examined by rearing males in bedding from unrelated adult males, their fathers, or their mothers. Males reared with bedding from their mothers showed delayed maturation of both androgen levels and seminal vesicle weights, whereas males exposed to bedding from unrelated males were not delayed. Males exposed to bedding from their fathers showed intermediate androgen levels but large seminal vesicles. Chemical cues from the family, particularly the mother, suppress reproductive development in male California voles. These results are discussed in the context of the puberty delay which occurs in natural populations of this species; puberty delay may be an adaptive strategy employed by young voles in times of high density and limited resources.