Abstract # 42:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation

Offspring Responses to Mothers' Resumption of Estrus in Rhesus Monkeys (Macaca mulatta)

J. Vandeleest1,2 and J. Capitanio1,2
1University of California-Davis, Psychology Department, One Shields Avenue, Davis, CA 95616, USA, 2California National Primate Research Center
     The breeding season poses many challenges for rhesus monkey infants; it is a time of both weaning conflict and maternal rejection as mothers mate to conceive their next offspring. We examined the effects of mother’s resumption of estrus on offspring behavior. Five minute infant focal observations were conducted during a baseline period prior to the breeding season (age=6.3 ± 0.5 months) and again when the mother was observed to engage in mating behaviors. There were no differences in pre-breeding behavior between infants of primiparous or multiparous mothers. During the breeding season, offspring of primiparous mothers (n=4) spent significantly less time in contact with their mother compared to offspring of multiparous mothers [n=8, ANOVA, a=0.05] and exhibited more distress vocalizations [Multivariate GLM, a=0.05]. Two distinct patterns of response were found for offspring of multiparous mothers, however; half of the infants increased contact with their mothers from baseline to the breeding season, and half decreased. There were no differences between these two sets of animals for any pre-breeding measure, and a preliminary examination of temperament data obtained during a 25 hour maternal separation at 3-4 months of age revealed no significant effects. This pilot study suggests that infant responses to the mother’s resumption of estrus are strongly influenced by the mother’s parity. The factors influencing the different responses for the offspring of multiparous mothers remains to be determined.