Using spatially explicit individual-based modelling to evaluate the ecological feasibility of big cat reintroduction: the example of the Arabian leopard

• Evaluated reintroduction feasibility of Arabian leopards using simulation modelling. • Simulated 4,032 scenarios across sex ratios, mortality, and re-enforcement strategies. • Anthropogenic mortality represented the main obstacle to population persistence. • Female-biased reintroductions led to higher population size. • Cost-benefit indices discouraged reintroductions under current conditions. Large predators have steadily declined worldwide due to habitat fragmentation, human-wildlife conflict, prey depletion, and persecution. Conservation translocations are essential for reversing these declines, yet success is often limited by small captive stocks, skewed sex ratios, poor post-release adaptation, and failure to breed in the wild. Large carnivores like the Arabian leopard ( Panthera pardus nimr ) face critical extinction risks, making reintroduction a crucial last resort. We used spatially explicit individual-based modelling in a region of the Middle East as an exemplar to illustrate an approach to assessing the ecological feasibility of reintroducing Arabian leopards into part of their historical range. We simulated 4032 scenarios over 50 years in Israel and the West Bank (IWB), evaluating factors such as population size, sex ratios, re-enforcement frequency, and human-induced mortality. Mortality critically influenced reintroduction success, with high risk causing rapid population declines despite repeated reintroductions. Supplementing females or couples yielded better outcomes for population size and genetic diversity, respectively. Even under low mortality, our exemplar populations would require continuous management. Habitat availability limited growth, making frequent, large re-enforcements inefficient in terms of return on investment. This study underscores the need for regional coordination in reintroduction efforts, ensuring sufficient prey and reducing mortality to improve population viability. Since the study began, geopolitical events have overtaken our original ecological focus. While this delays any local rewilding, it does not diminish the relevance of our approach for Arabian leopards more widely or other large carnivores in fragmented, human-dominated landscapes.