The influence of zoo visitors on the behavior of captive chimpanzees (pan troglodytes)

Antonocci, Brigitte
Beth Kaplin, PhD
Department of Environmental Studies
Does the presence of large numbers of human visitors within the socioecology of the zoo setting affect the social behavior of chimpanzees? The chimpanzee community at Honolulu Zoo was observed to assess how the size of viewing crowds affect the social behavior and stress level of zoo chimpanzees. One hundred twenty three hours of observations were taken over a twelve week-week period at the Honolulu Zoo on ten captive chimpanzees. An instantaneous scan sampling method was used to collect data. Crosstabulations were used for analyses. Detailed observations indicate that with increasing numbers of zoo visitors the chimpanzees showed declines in positive social behaviors, an increase in visitor directed aggression, and increase in community directed aggression and a decrease in affiliative behaviors. The results of this study suggest that increasing densities of zoo visitors does affect chimpanzee behavior and stress. Additionally, it is essential that the chimpanzees have an area within their daily enclosure that they may use to escape from the view of zoo visitors. My results also suggest that it is essential that all very young human infants be prohibited in the chimpanzee viewing area. It is important that we monitor social cohesiveness in wild ape populations that are subject to human intervention or tourism. Methods developed for this study may be applicable to wild populations to determine the number of human visitors that are tolerable for each population in question, independently. Additionally, results from this study could be used to bear on the effects of the presence of humans on wild populations.

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