Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Action: Guard habituated primate groups to ensure their safety/well-being Primate Conservation

Key messages

Read our guidance on Key messages before continuing

  • A controlled, before-and-after study in Rwanda, Uganda, and the Democratic Republic of Congo found that a population of mountain gorillas increased over 41 years after being guarded against poachers, alongside other interventions.

Supporting evidence from individual studies


A controlled, before-and-after study in 1967-2008 in tropical moist montane forest in Volcanoes-, Mgahinga-, and Virunga National Parks in Rwanda, Uganda, and the Democratic Republic of Congo found that a mountain gorilla Gorilla beringei beringei population where individual animals were closely guarded against poachers alongside ten other interventions, increased in size over time. Annual population growth was 4.1%, resulting in an overall population increase of 168% over 41 years. No statistical tests were carried out to determine whether this increase was significant. Increased protection through the guarding of gorillas explained 60% of the difference in growth rates between this population (treatment) and a second, unguarded population in the same area (control). The remaining 40% were likely accounted for by veterinary interventions for snares, respiratory disease, and other life-threatening conditions. As part of an ecotourism- and research project, gorillas in the guarded population were habituated to human presence, where visitors/researchers had to follow strict health procedures; these included keeping a safety distance to the gorillas, wearing face-masks, spending only a limited amount of time with gorilla groups, ensuring that visitors/researchers were healthy, and disinfecting visitor’s/researcher’s clothes, boots etc. Dead gorillas were clinically examined. The study does not distinguish between the effects of the different interventions mentioned above.

Referenced papers

Please cite as:

Junker, J., Kühl, H.S., Orth, L., Smith, R.K., Petrovan, S.O. & Sutherland, W.J. (2019) Primate conservation. Pages 439-491 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.