Intertroop kidnapping of a young infant in wild olive baboons (Papio anubis)

Abstract

On June 16, 2023, a juvenile female olive baboon (Papio anubis) in our study troop at the Uaso Ngiro Baboon Project in Kenya grabbed a ~3-week-old infant from another troop and released him near a high-ranking adult female in the study troop. This female, who was already pregnant, took the infant and treated him as her own, allowing him nipple access. The infant survived for over a month, which suggests the female produced some milk, at least initially, but he eventually died on July 24. Here, we describe the behaviours of all individuals involved in this rare event, and present possible proximate mechanisms and ultimate explanations for the behaviours observed. Rare events can reveal a species’ behavioural and physiological flexibility, and this one sheds light on the potential for infant stacking in baboons and the use of infants as a commodity within the social market of the troop.