Genetic structure and diversity within lethally managed populations of two mesopredators in South Africa

Abstract

Jackals (Canis mesomelas) and caracals (Caracal caracal) are considered major predators of small livestock on farms across South Africa, with both species being subjected to lethal control. Lethal management (i.e., culling) can result in differential responses in the population dynamics and demography of mesopredators. We examined the potential impacts that high population turnover, due to lethal management, may have on the genetic structure and diversity of jackal and caracal populations. We included mitochondrial markers to assess the movement of maternal lineages across the landscape as a proxy for dispersal. We further employed variable microsatellite markers to quantify levels of genetic diversity and relatedness among individuals. We found that high population turnover in both species may promote compensatory dispersal, which is consistent with the high levels of genetic diversity observed in both species. Structure analysis showed that the jackal population was comprised of 2 genetic clusters, while all the caracals belonged to a single nuclear genetic cluster. The weak differentiation between the jackal clusters (FST = 0.08), and the high level of inbreeding (FIS = 0.112) in the Central Karoo cluster, suggests that they likely represent demic populations. These data can be used as a baseline for ongoing population monitoring. Temporal monitoring of wildlife populations that are exposed to lethal management is important for a better understanding of the long-term effects on species ecology and survival success.