Social organization in the mountain nyala (Tragelaphus buxtoni) population in the Bale Mountains National Park, Ethiopia

Mountain nyala populations in the Bale Mountains National Park, Ethiopia, exhibit complex social structures with five distinct group types: all-male, all-female, male-female, female-juvenile, and male-female-juvenile. The study, conducted in 2009 and 2011, identified male-female-juvenile groups as the most frequent (31% of records) and largest (mean size: 18.5 individuals), containing over half (64%) of all recorded animals. Lone adults, predominantly males, accounted for 16.3% of groups but only ~2% of individuals. Group sizes ranged from 1 to 107, with a mean of 9.1 and typical size of 24. The findings reveal significant social flexibility, as group associations increased both the mean number and proportion of individuals per age/sex category. This research provides the first detailed baseline on mountain nyala social behavior, critical for conservation efforts in this endangered species.

Yosef, M., Addisu, A., & Girma, M. (2015). Social organization in the mountain nyala (Tragelaphus buxtoni) population in the Bale Mountains National Park, Ethiopia. International Journal of Biodiversity and Conservation, 7(2), 103–111. https://doi.org/10.5897/ijbc2014.0783