van Rooyen, N. T. | Search bioRxiv

bioRxiv2026

The Balancing Act: Olive baboon (Papio anubis) occupancy is associated with resource-related environmental variables rather than relative abundance of predators.

Understanding how the fear of predation acts as a driver of spatial distribution is fundamental to animal behaviour research, yet this relationship is not wholly understood in primates such as baboons. Olive baboons (Papio anubis) have evolved a diverse range of antipredator strategies that reduce, but do not eliminate, predation risk from the large carnivores they encounter across their broad geographic range. This raises a critical question: does the need to access essential resources outweigh the risk of predation when determining habitat selection? We addressed this question by examining the relative influence of three environmental factors and relative predator abundance on olive baboon occupancy patterns and detection probability in Serengeti National Park, Tanzania. Using data from 225 camera traps deployed by the Snapshot Safari program, we fitted three separate Bayesian occupancy models, each incorporating the same three environmental covariates (terrain ruggedness index, distance to nearest river, and Normalized Difference Vegetation Index, NDVI), together with the relative abundance of one of three principal predators (lion, leopard, or spotted hyena). This approach allowed us to assess whether environmental covariates associated with baboon occupancy remained consistent across different predator contexts. Baboon occupancy strongly increased with terrain ruggedness in all three models and consistently decreased with a greater distance to rivers. Vegetation greenness (NDVI) showed a positive association with baboon occupancy, though credible intervals narrowly overlapped zero. NDVI also showed a strong positive relationship with baboon detection probability. Associations between predator relative abundance and baboon occupancy varied between models: the relative abundance of lions and spotted hyenas showed no strong association with baboon occupancy, whereas the relative abundance of leopards was strongly correlated with baboon occupancy, consistent with shared habitat preferences. Our findings demonstrate that, independent of predator presence, olive baboon spatial distribution in the Serengeti is primarily and consistently associated with resource-related environmental features. This study expands our knowledge on the ecological factors that influence primate occupancy by showing that, for a behaviourally flexible species with diverse antipredator strategies, access to essential resources can outweigh spatial avoidance of predators in a multi-predator landscape.

ecology↗

bioRxiv2025

No evidence of reactive avoidance of baboons (Papio ursinus and Papio anubis) to the presence of predators

Withdrawal StatementThe authors have withdrawn this manuscript due to a duplicate posting of manuscript number BIORXIV/2025/646592. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author. The correct preprint can be found at DOI: 10.1101/2025.04.01.646592

ecology↗

bioRxiv2025

Absence of reactive temporal response of baboons to the occurrence of predators

Predators exert strong selective pressure on prey species, shaping their behavioral adaptations. Prey species use proactive responses, such as site selection and the adjustment of daily activity patterns to anticipate and avoid predation exposure. In contrast, reactive responses, including fleeing, referential signaling and retaliation, occur after encountering a predator to mitigate the immediate predation risk. The presence of a predator in an area can also generate longer-term responses, such as reactive avoidance, defined here as the temporary avoidance of the area following the passage of a predator. Such a long-term reactive response remains understudied in primates. To investigate reactive avoidance, we analyzed an extensive camera trap data set of 3,042 detections (defined here as a motion-triggered event of three pictures per trigger during the day and one picture at night) of both chacma (Papio ursinus) and olive (Papio anubis) baboons, including 6,958 detections of their main predators, lions (Panthera leo), leopards (Panthera pardus) and spotted hyenas (Crocuta crocuta), in four savanna sites (Madikwe Game Reserve, Tswalu Kalahari Private Wildlife Reserve and the Associated Private Nature Reserves, South Africa; Serengeti National Park, Tanzania). We examined whether baboons display species-specific reactive avoidance towards predators up to 72 hours after the detection of a predator using randomization tests. We found no significant decrease in baboon presence (defined as the number of baboon detections) 0 to 24 hours, 24 to 48 hours and 48 to 72 hours after the detection of any predator species. These results suggest that baboons may not display reactive avoidance and rely on alternative predator-avoidance strategies, such as proactive avoidance or aggressive retaliation, to mitigate predation risk.

animal behavior and cognition↗