Control of postpartum mating behavior in free-ranging rhesus monkeys

This paper explores the effect that a dependent rhesus macaque infant (Macaca mulatta) has on the timing of its mother's resumption of mating. Toward this end, behavioral data from the rhesus populations at Tughlaqabad, India, and Cayo Santiago, Puerto Rico, are compared. Specifically, the intervals between parturition and subsequent resumption of mating for individual parous females are examined in order to shed light on the relative importance of environmental and internal factors (such as lactational infertility) in the control of rhesus mating behvior. At both study sites it was found that the later a given female gave birth during a birth season the shorter was her parturition-mating interval and the younger was her infant when she resumed mating activity. It is suggested that this finding is the result of an interaction of environmental and internal factors; both act in concert to determine how soon after parturition a particular rhesus female will resume mating activity.