Anthropogenic movement results in hybridisation in impala in southern Africa

Abstract

Hybridisation caused by anthropogenic movements of animals is a conservation concern. Black-faced impala (Aepyceros melampus petersi) are endemic to north-western Namibia and south-western Angola and are geographically isolated from common impala (A. m. melampus). Common impala have been translocated into the black-faced impala range creating a hybridisation risk. We validated 13 microsatellite markers for the detection of recent hybridisation events. We used these markers to assess the genetic variation and differentiation among impala within Etosha National Park (NP), Southern Cross Private Game Reserve (SCPGR), Namibia, and private game ranches across South Africa. We confirmed that “black-nosed” impala in South Africa were A. m. melampus, thus providing more evidence that the black blaze on the face cannot be used to distinguish between the two subspecies. We detected four hybrids and one common impala on SCPGR. These five individuals were removed from SCPGR at time of sampling. We found two potential hybrids in southern Etosha NP. Further sampling of animals within Etosha NP is recommended to determine the extent of hybridisation within the park. The Namibian Ministry of the Environment & Tourism is developing a management plan for black-faced impala across Namibia that includes genetic testing for hybrids.