The Size, Demography, and Distribution of Cambodia's Largest Elephant Population Revealed Using Traditional Genetic Tools and a Novel SNP Panel

Wildlife adaptive management is often constrained by gaps in population data. This study aimed to evaluate the population size and demography of elephants occurring in eastern Cambodia. A fecal mark-recapture study was conducted in two adjacent protected areas: the Phnom Prich and the Srepok Wildlife Sanctuaries. Population parameters were assessed using microsatellite, single nucleotide polymorphism and sex determination DNA markers. Age structure was assessed using bolus size. A total of 156 unique genotypes were identified and results indicate both sanctuaries support 381.5 individuals (95% CI = 282-549), Cambodia's largest population, with an N_e of 59.8 (95% CI = 46.3-79.6). We found no evidence for elephants crossing National Road 76, indicating that it may now divide the population into two groups with more than 100 individuals each. However, each with an N_e < 50 and low numbers of neonates/juveniles raise concerns about their persistence. To prevent further fragmentation and ensure fluidity of movement, new strategies are required to promote forest connectivity and minimize anthropogenic disturbances within and between these two protected areas.