Evaluating the Genetic & Demographic Integrity of South Africa's Cheetah Metapopulation

In 2011, the Endangered Wildlife Trust launched the Cheetah Metapopulation Project to provide coordinated relocation management to a group of 300+ cheetahs that were removed from commercial farmland in Namibia & South Africa. These cheetah were subsequently introduced onto smaller, fenced, privately held reserves in South Africa. This paper addresses 2 challenges associated with the cheetah metapopulation’s long-term viability: the ecological capacity of the fenced reserves and the genetic diversity of the reserve cheetahs. Density prediction models based on prey biomass were used to project carrying capacity estimates for 21 reserves. Three equations were used in order to capture differences in prey characteristics. When compared with actual densities, the model projections did not provide adequate estimates of carrying capacity. The finding implies that prey biomass alone cannot explain cheetah density. Heterozygosity, or gene diversity, was used to evaluate the population’s genetics so that future analyses can capture a loss or gain in diversity. As a reference population, 33 cheetah individuals from South Africa’s free roaming population were genotyped using 16 microsatellite loci. Forty three of the reserve cheetahs were genotyped at the same loci. This data were used to calculate and compare heterozygosity for the two populations, enabling a comparison of genetic diversity between the free roaming cheetahs and the metapopulation cheetahs which are actively managed in fenced reserves. Overall, the reserve population has higher levels of heterozygosity than the free roaming population, suggesting that genetic diversity has been maintained on the reserves. This is possibly due to a temporary outbreeding effect from ‘artificial migration’ (translocation between reserves). This suggests that the reserve cheetahs would not benefit from crossbreeding with the free-roamers, however the free roamers would benefit. As the reserve population approaches its overall capacity, mating suppression will be required to avoid selling these wild cheetah into captivity. Genetic information should continue to be utilized for management, in order to further increase the population’s biological fitness over the long term.