Landscape genetics and behavioural ecology of mountain nyala (Tragelaphus buxtoni) in the Southern highlands of Ethiopia

Abstract

Many African wildlife species are at risk of extinction as a result of habitat loss and fragmentation associated with human influence. Among these is the endangered antelope, mountain nyala (Tragelaphus buxtoni), endemic to the highlands of southern Ethiopia. I implemented a multidisciplinary approach, including geographic information system (GIS), satellite image analysis and non-invasive genetics to provide basic knowledge required for the conservation this species. My study reveals new insight on the distribution and abundance of mountain nyala. I estimated the population to 3700 individuals and defined a 3200 km2 area of suitable habitat that needs to be prioritized for the future conservation of the species. The genetic data indicated that the gene flow between the different mountain nyala populations is limited. With the rapidly expanding human population in the Ethiopian highlands maintaining habitat connectivity will be important to protect the mountain nyala from extinction. I also discovered that the diet of the mountain nyala is more diverse than previously known. They were considered strict browsers (leaf eaters), but I documented a high degree of overlap between the grazing areas of livestock and the mountain nyala. This means that they are competing over resources and highlights that livestock should be restricted in areas where the mountain nyala is protected. This study furthermore shows that the mountain nyala seeks human settlements during nights to avoid spotted hyenas (Crocuta crocuta) that are nocturnal predators. We describe this phenomenon, through the “human shield hypothesis”, as a flexible strategy that can vary in space and time with relative differences in the levels of natural predation and human hunting. The approaches used in this thesis may be useful also for the study and conservation of other wildlife species inhabiting areas of increasing human encroachment.