Population structure and group size of geladas (Theropithecus gelada) at Chenek, Simien Mountains National Park, Ethiopia

Geladas (Theropithecus gelada) in Simien Mountains National Park, Ethiopia, exhibit a population structure dominated by a single reproductive male per band, accompanied by multiple females and offspring. A study counting 397 individuals over 18 months revealed a significant sex ratio skew (1:1.25 adult males to females) and distinct age-class distributions, with juveniles and infants comprising a substantial portion of the population. Fission-fusion dynamics were observed among bands, suggesting flexible social organization. However, geladas at Chenek face competition for food, including theft from locals and tourists, indicating human-wildlife conflict. The research highlights the need to minimize anthropogenic disturbances to preserve this species' natural behavior and habitat within UNESCO-listed Simien National Park.

Ejigu, D., & Bekele, A. (2017). Population structure and group size of geladas (Theropithecus gelada) at Chenek, Simien Mountains National Park, Ethiopia. African Journal of Ecology, 55(4), 564–572. Portico. https://doi.org/10.1111/aje.12389