Demography and dynamics of mountain nyala Tragelaphus buxtoni in the Bale Mountains National Park, Ethiopia

A significant decline of 45% in the mountain nyala population (Tragelaphus buxtoni) was observed in Bale Mountains National Park, Ethiopia, between 2003 and 2005, with an annual decrease of 2%-5%. The study attributed this reduction to anthropogenic factors such as competition with livestock for forage, habitat encroachment, and poaching. Population density varied significantly between sub-populations (Dinsho Sanctuary and Gaysay/Adelay), with the Dinsho group being isolated, potentially limiting their access to mates and suitable habitats. The population size was estimated at 830-908 individuals, despite an increase in mean density due to habitat contraction. Demographic parameters remained stable over three years, suggesting that the decline was not due to random variations but likely driven by human activities.

Mamo, Y., Pinard, M. A., & Bekele, A. (2010). Demography and dynamics of mountain nyala Tragelaphus buxtoni in the Bale Mountains National Park, Ethiopia. Current Zoology, 56(6), 660–669. https://doi.org/10.1093/czoolo/56.6.660