Behavioral Responses of Gorillas to Habituation in the Dzanga-Ndoki National Park, Central African Republic

Habituating primates: processes, techniques, variables and ethics

“…Moreover, as the primates become habituated to your presence, there should be an increase in the duration of average contact time, and decreases in flight, avoidance and display behaviours. Work with both lowland gorillas and Geoffroy's tamarins (Saguinus geoffroyi) has shown that day ranges decreased with habituation (Rasmussen, 1998;Blom et al, 2001). The ratio of habituation time to observation time should change, but be patient and do not have high expectations: mean contact time with lowland gorillas increased from about 7 minutes to only 20 minutes over three years (Blom et al, 2001).…”

“…Work with both lowland gorillas and Geoffroy's tamarins (Saguinus geoffroyi) has shown that day ranges decreased with habituation (Rasmussen, 1998;Blom et al, 2001). The ratio of habituation time to observation time should change, but be patient and do not have high expectations: mean contact time with lowland gorillas increased from about 7 minutes to only 20 minutes over three years (Blom et al, 2001). Consistency of observers, or possible 'hand-over' periods may be helpful if different people are likely to be involved in habituation, although this should be avoided during the early phases.…”

“…Hamadryas baboons (Papio hamadryas) could be approached to 60 m during daily marches within a year, but to be able to walk among them took about two years (Kummer, 1995). Only after a year of repeated contacts did lowland gorillas' reactions change from Rylands, 1986;Barton & Whiten, 1993;Sterling, 1993;Cowlishaw, 1997;Passamani, 1998;Rasmussen, 1998 Schaller, 1963;Kummer, 1995;Butynski, 2001 2--5 years Bonobo (Pan paniscus), chimpanzee (Pan troglodytes), lowland gorilla (Gorilla gorilla gorilla) Boesch-Achermann & Boesch, 1994;Susman, 1984;Blom et al, 2001 aggression to ignore (Blom et al, 2001), yet titi monkeys (Callicebus personatus personatus) were habituated without systematic effort in about 12 weeks while following marmosets (Callithrix geoffroyi) (E. Price, personal communication, 2002).…”

“…Schaller, 1963;Kummer, 1995), as habituation has generally been viewed as a means to an end (Tutin & Fernandez, 1991). The few studies that have quantified primate behaviour in relation to habituators describe the process with African great apes (Grieser Johns, 1996;van Krunkelsven et al, 1999;Blom et al, 2001). As we become increasingly aware of the potential effects of observer presence on primate behaviour, and especially the potential risks of close proximity with humans, it behoves us to measure as much as possible about the habituation process.…”

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.…”