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Title: Habituation, avoidance strategies, and social learning in wild Bornean orangutans in Gunung Palung National Park, Indonesia
Habituation, or the process of an animal becoming comfortable with human observers, is an essential part of wild primate observational studies. Despite the importance of this process, questions remain as to what counts as habituated for a particular species, how individuals and species react to humans, and how age-sex classes differ in these responses. To address these questions, we analyzed data from over 25 years of research on wild Bornean orangutans from Gunung Palung National Park, Indonesia, drawing from 8,383 follows and 82,413 hours of observation. We categorized the degree of agitation with humans by totaling the number of alarm vocalizations, giving each follow a score of 1-10. We then looked at behavioral measures using a GLMM to control for individual and food availability. This revealed that individuals with the highest vocalization scores spent a greater percentage of the day traveling (b=40.5, p < 0.0001), stayed higher in the canopy (b=16, p < 0.0001) and spent less time eating (b=205, p < 0.0001) than did animals that did not vocalize. Our analysis also revealed a less common, but frequently observed, opposing response to humans, which was to hide, often inside of a day nest, and emit no vocalizations. Individual orangutans were observed to switch between these two ’strategies’ to evade human observers. We discuss the implications of this behavior as well as present evidence that the reaction of other orangutans mediates the response of focal individuals to humans, suggesting the importance of social learning in this behavior.  more » « less
Award ID(s):
1638823 0936199
NSF-PAR ID:
10186110
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
American journal of physical anthropology
Volume:
171
Issue:
S69
ISSN:
0002-9483
Page Range / eLocation ID:
39
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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