Seasonal trade-offs between resources and human activity shape habitat selection in reintroduced scimitar-horned oryx in the Sahel

Background The spatial distribution of Sahelo-Saharan antelopes is affected by environmental and anthropogenic factors that exhibit strong seasonal variation. Understanding how seasonal factors modulate movement decisions and space use of scimitar-horned oryx reintroduced into the Ouadi Rimé - Ouadi Achim Faunal Reserve (Chad) will support ongoing species conservation activities and guide habitat management efforts. Methods We combined more than 1.5 million GPS collar locations fitted to 262 individuals over 8 years, in situ data, and remote sensing variables in integrated step selection functions (iSSFs). We competed all possible combinations of environmental and anthropogenic covariates to investigate the habitat preferences of reintroduced oryx. Results Scimitar-horned oryx strongly selected for higher wooded vegetation density during the hot dry season and selected more weakly for this factor during the rainy season. This selection leads to an unexpected overlap between the oryx habitat preferences and human activity sites during this period. Oryx were also negatively associated with burned areas during most of the year – except for the hot dry season. Similarly, oryx exhibited weak selection for depressions during the rainy and cool dry seasons, but significantly intensified selection for depressions during the hot dry season. Conclusions During the hot dry season, both oryx and people prefer wooded areas that provide a much-needed thermal refuge from high temperature. This seasonal convergence of habitat preferences may increase interactions between oryx, people, and livestock during this period, and heighten the risk of human – wildlife – livestock conflict within the reserve. However, limited data are available on human activities and livestock movements within the reserve, as well as typical oryx behavioral responses to human presence. Our results therefore emphasize the need for spatially explicit information about livestock movements, particularly with reference to woody cover density during the hot dry season, to mitigate potential conflicts between reintroduced antelope and humans grazing livestock in the reserve.