Habituation of Wild Chimpanzees (Pan troglodytes) of the South Group at Taï Forest, Côte d’Ivoire: Empirical Measure of Progress

Abstract

The last part of the chimpanzee (Pan troglodytes) habituation process of the Taï South Group was monitored over 2 years (1994–1996), during which all males and most of the females became habituated to observation by humans. The time needed (5–7 years) to habituate the community was similar to that recorded for the Taï North Group and is comparable to other populations studied in Africa. Variation emerged in habituation rate: males were habituated earlier than females, and among females, sexually cycling individuals were habituated faster than non-cycling females. Such differences may be a function of both the methods used to find the chimpanzees and the sex of the individual. Reproductive status and individuality may also have influenced habituation rates by affecting the number of contacts required to habituate a chimpanzee to neutral humans.

Socially learned habituation to human observers in wild chimpanzees

“…As at the two other sites, we never provisioned the chimpanzees with food and followed a habituation protocol very similar to Gashaka and near identical to that employed in Tai (Bertolani and Boesch 2008 ). It is possible that the relatively slow habituation rates at Gashaka can be partially explained by difficult terrain, but this is unlikely a sufficient explanation.…”

“…However, our data suggests that the presence of the two habituated females at Waibira was at least partly responsible for the dramatic difference in habituation speed. Their presence may have increased the likelihood that non-habituated individuals would remain in contact with the observers, thus acting as 'catalysts' for future encounters and increasing contact frequency, a necessary component in achieving habituation (Bertolani and Boesch 2008 ).…”

“…In chimpanzees (Pan troglodytes), habituation is particularly timeconsuming. Large and usually densely forested home ranges, complex fission-fusion social structure, and a long history of conflict with humans, make this species relatively difficult to habituate in comparison with other primates (Morgan and Sanz 2003 ;; Bertolani and Boesch 2008 ). In one well-documented case, the North community of Taï Forest, Côte d'Ivoire, chimpanzees were only sighted for 1 % of observation time during the first 2 years of habituation (Boesch and Boesch 1990 ).…”

Does watching a monkey change its behaviour? Quantifying observer effects in habituated wild primates using automated radiotelemetry

“…Rattenborg et al 2008). However, wild animals often react strongly to humans, either fleeing, or producing threats or alarm calls in response to observer presence (Williamson & Feistner 2003;Blom et al 2004;Bertolani & Boesch 2008;Aguiar & Moro-Rios 2009). These negative reactions present a problem for researchers trying to study animal behaviour under natural conditions.…”

“…Grieser Johns 1996;Van Krunkelsvewn et al 1999;Blom et al 2004;Bertolani & Boesch 2008;Jack et al 2008). Other measures of behaviour, including day range (Rasmussen 1998;Cipolletta 2004) and activity budget (Williamson & Feistner 2003) also tend to change as the amount of time an animal has been under observation increases.…”