A Camera Trap Study of Diel Activity and Crevice Use in the Critically Endangered Pancake (…)

ABSTRACT

Understanding a species' activity patterns is key to explaining its ecological role and survival strategies and can guide effective conservation planning. We used camera traps deployed at rocky outcrop crevices in Tarangire National Park and an adjacent village in northern Tanzania to study the diel activity of the critically endangered pancake tortoise (Malacochersus tornieri). We characterized the species' daily activity rhythm using kernel density estimation, recorded the potential predators visiting crevices, and applied a Bayesian single-season occupancy model to assess the influence of ambient temperature, rainfall, vegetation cover (NDVI), and terrain ruggedness (TRI) on tortoise activity and detection. Tortoise activity followed a unimodal, diurnal pattern, with most movements concentrated between late morning and early afternoon (10:00–16:00), and only a few activity incidents were recorded at night. We recorded ten potential predator species visiting crevices, although predator detections were infrequent. Among the environmental variables tested, only ambient temperature received clear support, and the hierarchical model attributed this effect to detection rather than occupancy: per-occasion detection probability showed a strong positive increase with temperature (standardized coefficient = 2.44, 95% credible interval 1.36–3.82), consistent with temperature-dependent emergence from crevices in this diurnal ectotherm. Estimated occupancy was high (ψ = 0.85), and substantial among-crevice variation in baseline detectability highlighted the importance of fine-scale crevice microhabitat. Our findings advance understanding of the behavioural ecology and habitat use of the pancake tortoise and provide a basis for refining management and conservation strategies for this critically endangered species.