Abstract
The contemporary genetic diversity of the cheetah (Acinonyx jubatus) has been the focus of several studies, which have revealed very low levels of variation. Different hypotheses have been proposed to explain this pattern of low diversity, and require additional scrutiny. Here, we used published microsatellite data and coalescence-based analytical methods to explore the historical demography of the largest free-ranging cheetah population, aiming to assess whether present-day diversity may have been impacted by a historical demographic decline. Our results support the hypothesis of a historical (and most likely gradual) demographic decline over the past ~10,000 years, leading to a present-day N e ranging from 700 to 1,600 individuals. This decline was likely induced by climate-driven vegetational shifts affecting habitat suitability and possibly also interspecies interactions with prey and competitors. These results help clarify the demographic history of cheetahs in southern Africa and its impact on the current genetic diversity of this population.