Influence of anthropogenic environments on the activity patterns and vigilance of Cape chacma baboons (Papio ursinus ursinus) in the Garden Route, South Africa

Abstract

Anthropogenic activities shape animals time allocation and risk perception, yet its immediate behavioural impacts on primate species remain poorly quantified. In the present study, variation in activity budgets and vigilance were analysed in three Cape chacma baboon (Papio ursinus ursinus) troops inhabiting contrasting anthropogenic environments in South Africas Garden Route: Madiba (in a peri-urban campus), North (in an intermediate area), and Outeniqua (in a more rural area). From March to June 2024, a total 84 h of observations were recorded yielding 343 scan samples, and modelled behaviour as a function of troop and environmental covariates (weather, habitat openness, car and human presence). Feeding dominated overall time allocation (35.4%), with no whole-budget differences among troops, but behaviour-specific contrasts emerged. Outeniqua troop inhabiting the more rural area relied significantly less on human-derived foods than Madiba and showed less running than both Madiba and North. In addition, level-3 vigilance (active/intense scanning) was higher in the troops frequenting more anthropogenic environments (Madiba, North) than in Outeniqua, suggesting that vigilance is a particularly sensitive response to human exposure. Finally, habitat openness was negatively associated with affiliative interactions, and car presence was negatively associated with resting. These results provide partial support for hypothesised disturbance effects, with shifts in behavioural sub-categories without overall budget change, clarifying how anthropogenic disturbance can restructure primate time allocation and risk perception. Such immediate behavioural responses should offer actionable insight for evidence-based conservation and human-baboon conflict mitigation.