Habituation of western gorillas: the process and factors that influence it

Abstract

Habituation of western gorillas to human presence is generally an expensive, lengthy and difficult process. Here we describe the habituation process for two groups of western gorillas at the Mondika Research Center, with the hope that the lessons we learned will facilitate future gorilla studies. We expand upon earlier studies by describing the process through complete habituation for both males and females, and for more than one group. The major obstacle to habituation was developing sufficient tracking skills to follow gorilla trail on a daily basis. Once this was achieved, the silverback became semi-habituated (i.e. ignoring human presence during half of contacts) within a year, although the majority of group females continued to avoid humans. As female presence at contacts increased, a period of male recidivism followed, requiring an additional year before his complete habituation was reached. Habituating the females took longer than the male, but we found, contrary to earlier studies, that it consisted of the same stages, including avoidance, aggression, and curiosity before habituation. We compare results between groups and across sites and discuss how factors such as tracking abilities, group size and cohesion, population density and home range overlap, and the manner of approaching gorillas during contacts influence the habituation process.

Allostatic load and biological anthropology

“…One possible coping mechanism is distance. Western lowland gorilla groups have been observed foraging up to a few hundred meters apart from one another (Doran-Sheehy, Derby, Greer, & Mongo, 2007). This large range likely lowers the risk of receiving aggression for females who are not foraging near the silverback.…”

From vision to narrative: A trial of information-based gorilla tourism in the Moukalaba-Doudou National Park, Gabon

“…It seems difficult, however, to introduce gorillawatching tourism such as that conducted in east Africa, for the following reasons. First, western gorillas are difficult to habituate (Doran-Sheehy et al 2007). In MDNP, as noted above, it took about six years to habituate a single group of 20-22 individuals ).…”

“…Second, the visibility of gorillas in MDNP is low. Lowland gorillas are very shy, and even the habituated gorillas exhibit stress responses when contact with human ob- servers increases (Blom et al 2004, Doran-Sheehy et al 2007, Fujita et al 2009). Therefore, observers must keep a distance of at least 20-30 m from them, to prevent disturbing their natural activities and to minimize their impacts on the gorillas' health status.…”

Regional Action Plan for the Conservation of Western Lowland Gorillas and Central Chimpanzees 2015–2025

“…Gorilla habituation has been attempted at other sites, but it is challenging, not always successful and should only be undertaken with careful planning and evaluation (Macfie & Williamson 2010). Human presence and the process of habituation are known to cause stress in gorillas (Shutt et al 2014) and alter their activity, levels of aggression and movement patterns (Cipolletta 2003;Blom et al 2004;Doran-Sheehy et al 2007;Klailova et al 2010). Guidelines for great ape tourism and habituation (Macfie & Williamson 2010;Williamson & Feistner 2011) recommend that impact studies and monitoring play an integral part of habituation and tourism projects.…”