Are baboon infants Sir Phillip Sydney's offspring?

Data on mother-offspring interactions in chacma baboons (Papio cynocephalus ursinus) were used to test predictions arising from Bateson's (1994) dynamic assessment model of mammalian weaning conflicts. The results provide preliminary support for this model. Infants, rather than mothers, controlled the amount of investment received in the early postnatal period and infants were motivated to begin foraging in the absence of maternal rejection. Furthermore, seven out of 10 infants did not display any tantrum behaviour during observations throughout the first year of life. Only those infants considered to be vulnerable to a seasonal reduction in weaning foods displayed high level tantrum behaviour that was accompanied by an increase in the amount of investment received from their mothers. Habitat quality is suggested to be critical in determining the success of a transition to independent foraging both within and between habitats, with mothers being sensitive to this and responding appropriately to infants who require increased investment. The high intensity tantrum behaviour is necessary to convey unambiguous information to a mother with imperfect knowledge of the offspring's state, and to convey the urgency of need, enabling infants to break into maternal schedules.