Can I Have a Bite? The Influence of Infant Begging on Food Sharing in Capuchin Monkeys (Sapajus Libidinosus)

In primates, food sharing from mothers to infants may serve two main functions: supporting offspring nutritional needs (nutritional hypothesis) and facilitating the acquisition of dietary knowledge, such as what and how to eat (informational hypothesis). We investigated these hypotheses in a wild population of bearded capuchin monkeys Sapajus libidinosus, at Fazenda Boa Vista, Brazil. We analyzed 194 h of footage of 10 infants filmed over their first 18 months of life using focal animal sampling. Mothers shared food exclusively in response to infant solicitation, with solicitation events observed across 48 mother feeding episodes. Infants were successful in obtaining food in 29 bouts but failed in 19. In 15 of the 29 successful bouts, mothers only shared food after repeated solicitations, suggesting that food sharing involves a negotiated process. We found partial support for the nutritional hypothesis: food sharing increased as the infants aged. Infants also solicited more high-quality and hard-to-process food items, but food sharing did not differ according to these food categories. Additionally, mothers were less likely to share lizards. Our findings suggest that food sharing in capuchins is driven primarily by infant begging, rather than active maternal investment, highlighting the dynamic interplay between mother and infant in promoting infant development.