Dispersal and reproductive careers of male mountain gorillas in Bwindi Impenetrable National Park, Uganda

Research on male mountain gorillas in Bwindi Impenetrable National Park, Uganda, reveals that at least 25% of dispersing males eventually form new social groups, challenging previous assumptions about their reproductive success. The study, spanning 1993 to 2017, also documents rare cases of dispersal by immature and old males, as well as the only known instance of a fully mature male immigrating into a breeding group. Using genetic tracking, scientists found no significant differences between Bwindi and Virunga populations in terms of dispersal age, proportion of dispersing males, or dominance tenure length, suggesting ecological variability does not lead to life history differences. Male gorillas employ varied strategies—such as solitary dispersal, group fissioning, usurping alpha males, or inheritance—to attain alpha status, contributing to the mixed one-male and multimale social structure observed in both populations.

Robbins, M. M., Akantorana, M., Arinaitwe, J., Kabano, P., Kayijamahe, C., Gray, M., Guschanski, K., Richardson, J., Roy, J., Tindimwebwa, V., Vigilant, L., & Robbins, A. M. (2019). Dispersal and reproductive careers of male mountain gorillas in Bwindi Impenetrable National Park, Uganda. Primates, 60(2), 133–142. https://doi.org/10.1007/s10329-019-00718-z