Mother-infant relationships in wild Guinea baboons (Papio papio)

Abstract

During infancy, primates are heavily dependent on their mothers for nursing, transport, and thermoregulation, but also benefit from associating with their mothers for protection and social support. Furthermore, the mother acts as a role model for social learning, facilitates the interaction with the physical environment and the integration into a broader social network. The repeated interactions and reciprocity between mother and infant, along with the time that they spend together, lead to the formation of the mother-infant bond, which is typically recognised as the strongest social bond in the life of primates. The relationship between mothers and infants is dynamic, and they typically spend most of the time in contact and in close proximity just after infants have been born, and mothers frequently nurse and carry their infants, but soon enough time in contact, carrying, and nursing progressively decreases, and proximity increases as mother and infant move along infancy.Weaning is a period typically marked by behaviours of maternal rejection and increase of distance between mother and infant promoted by the mother. By the end of infancy, individuals will be independent from their mothers, and will therefore be able to move and feed by themselves. Even though the mother-infant dependency decreases as infancy progresses, not all mothers behave in the same way towards their infants. The individual variation in maternal care is known as mothering style, and it can have marked differences in the fate of infants' development and survival. Generally, mothers that are more protective produce infants that have higher survival rates and grow faster, and infants of rejecting mothers have lower survival and grow slower, but reach independence earlier.The aim of this thesis was to investigate the mother-infant relationships in wild Guinea baboons living in the Niokolo-Koba National Park in Senegal. Guinea baboons live in a multi-level social organisation, with "units" at their base, several units forming "parties", and several parties grouping to form "gangs". Guinea baboons form strong social bonds with other males, have low levels of aggression, and show high spatial tolerance. Dispersal is female-biased, and even though females form linear and steep dominance hierarchies at the unit level, rank does not depend on kin. As a consequence of females transferring to other units, parties, or gangs, offspring might be left behind if a mother decides to disperse. Altogether, along with the fact that Guinea baboons live in a tolerant social system with regards to their social relationships, make Guinea baboons an interesting species to study mother-infant relationships. Summary 2In chapter 2 I provide a description of the behaviours between mothers and infants throughout infancy. I show that, similar to all primates, mothers and infants spend most of their time in contact and proximity in the early stages of infancy, and these behaviours, along with carry and nipple contact, decrease over time. Other behaviours, however, are very...