Behavioural and physiological responses of chacma baboons (Papio ursinus) to wildfire in the Cape Peninsula of South Africa

In an ecological context, ‘flexibility’ refers to an animal’s ability to respond immediately to environmental stimuli through physiological and behavioural adjustments. Specifically, primates exhibit a high degree of ecological flexibility, which allows them to persist through environmental changes that vary in duration and predictability. To cope with the variability of conditions within their habitats, baboons have evolved flexibility in ranging behaviour, social behaviour, and diet. Natural disasters are predicted to increase across the globe, and many parts of the world are experiencing longer wildfire seasons and higher wildfire frequencies than ever before. The aim of this study is to use an existing data set to assess how baboons responded, behaviourally and physiologically, to an extensive wildfire. I compare home range use, activity budgets, faecal glucocorticoid concentrations, and urinary C-peptide concentrations three months after the fire to the same three months in the previous year for the same 16 adult females. In the months following the fire, the baboons had a larger spatial range compared to the same months in the year prior. The additional area incorporated unburnt areas into their home range, which were preferentially used over burnt areas. Behavioural adjustments included notably less time spent engaging in social behaviours than in the year prior. Perhaps most surprisingly, postfire physiological indicators did not suggest high levels of psychological, energetic, or nutritional stress, as glucocorticoid concentrations were significantly lower post-fire compared to the year prior, while C-peptide concentrations were not significantly different between the two periods. The troop appears to have benefited from a surfeit of exotic pine seeds that were released by pine trees as a result of the fire. This unexpected nutritional windfall, in addition to the inclusion of vineyards within their ranging patterns, may explain why there were no physiological indicators of nutritional stress despite the loss of most above ground biomass. Despite suffering the loss of 12 troop members in the fire and injury to a further 12 individuals, adult females in the Tokai troop were able to adjust to a severe and extensive change to their home range. Although primate ecological flexibility has been widely documented, this is the first study to explore the behavioural and physiological responses of baboons to extensive habitat changes resulting from a wildfire, and the potential implications for the management of wildlife on the urban edge