Population Viability Analysis of African Elephant in Yankari Game Reserve

Population viability analysis (PVA) is a powerful tool for evaluating the long-term persistence prospects of wildlife populations and identifying the management interventions most likely to improve survival probabilities. The African elephant population of Yankari Game Reserve in Bauchi State, North East Nigeria, is among the last significant elephant populations in West Africa but faces threats from poaching, habitat degradation, and human-elephant conflict. Systematic population monitoring data have accumulated over recent years, providing a foundation for rigorous PVA. This study develops a population viability analysis for the Yankari elephant population using VORTEX simulation software and data from aerial surveys, individual identification records, and mortality records spanning 2015 to 2023. Demographic parameters including birth rate, mortality by age class, sex ratio, and population size were estimated from field records. Stochastic simulations model population trajectories over 100 years under baseline conditions and alternative management scenarios. Results indicate that under current conditions, the probability of population extinction within 50 years is 22 percent, rising to 64 percent if poaching rates increase by 15 percent. Targeted anti-poaching interventions reducing annual poaching mortality to historical low levels extend median population persistence by 38 years. The study recommends intensified anti-poaching investment as the highest-return intervention for elephant conservation at Yankari, supplemented by calving season surveillance and range expansion to reduce density-dependent stress. Keywords: population viability analysis, African elephant, Yankari Game Reserve, North East Nigeria, PVA