Abstract
Abstract
Social relationships can buffer individuals against environmental challenges, reducing the physiological costs of disturbance. Assessing how social and environmental conditions jointly shape physiological stress is critical for predicting individual responses to disturbance, particularly in managed populations. We evaluated whether social and environmental stressors act additively or whether social context modifies physiological responses to environmental challenges. We combined behavioural data and faecal glucocorticoid metabolite samples from a small, intensively monitored population of African elephants (
Loxodonta africana
) in a fenced reserve. Using a Bayesian framework, we tested how social factors interacted with variation in the biophysical environment, including natural environmental and anthropogenic disturbances, to predict glucocorticoid concentrations. Natural environmental variables, including weather, water availability, and season, did not predict glucocorticoid concentrations. In contrast, helicopter use, a common management intervention, was associated with higher glucocorticoid concentrations. Social effects were context dependent. Following disturbance, low-ranking individuals showed higher glucocorticoid concentrations than high-ranking individuals, whereas this pattern reversed under low-disturbance conditions. Individuals with more social connections had lower glucocorticoid concentrations, but this effect was evident only under non-disturbance conditions. Measures of betweenness centrality did not predict glucocorticoid levels. These results demonstrate that social factors mediate physiological responses to anthropogenic disturbance and that management actions can impose uneven physiological costs across individuals. Quantifying interactions between social factors and the biophysical environment may improve conservation and management strategies for social species. Integrating physiological responses to interactions between social factors and the biophysical environment can guide conservation strategies and improve management interventions in social species.
Lay summary
Conservation actions can reshape the environments animals live in and the social systems they depend on, with consequences for well-being and survival. We show that in African elephants, human disturbance increases physiological stress, but social status determines who is most affected. Lower-ranking individuals show stronger stress responses after disturbance, whereas patterns reverse under non-disturbance conditions. Social connectedness can also reduce stress, although this effect varies across environmental conditions, highlighting how social factors and environment jointly shape physiological responses.