Abstract # 13311 Poster # 107:

Scheduled for Thursday, August 22, 2019 06:00 PM-08:00 PM: (Alumni Lounge) Poster Presentation


CHIMPANZEE (PAN TROGLODYTES) AND WESTERN LOWLAND GORILLA (GORILLA GORILLA GORILLA) RETIRING BEHAVIOR: COMPARING VERTICAL SPACE USE IN TWO EXHIBITS AT LINCOLN PARK ZOO

S. C. Earl, L. M. Hopper, A. C. Kwiatt and S. R. Ross
Lincoln Park Zoo, Lester E. Fisher Center for the Study and Conservation of Apes, Chicago, Illinois 60614, USA
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     Wild chimpanzees frequently make arboreal nests, while gorillas mostly nest on the ground. We aimed to understand whether zoo-housed apes’ use of elevated spaces for retiring differed between species and across exhibits. Using a pre-planned exhibit switch at Lincoln Park Zoo (Chicago, IL), we compared where (elevated or on-ground) two groups of apes performed retiring behaviors (inactive, sleeping, and nest-building behaviors recorded between 3-5pm). We studied a group of six chimpanzees and a group of four gorillas in both of two exhibits of similar size and configuration. We predicted chimpanzees would be more likely to retire in elevated locations compared to gorillas, irrespective of exhibit. Ninety-seven hours of focal data were collected with chimpanzees in Exhibit A and gorillas in Exhibit B (November 2017-January 2018) and an additional 153 hours after the groups switched exhibits (November 2018-January 2018). We found a significant effect of exhibit (F=11.23, p=0.0085) but no effect of species (F=1.266 p>0.05), nor an interaction effect (F=0.567, p>0.05) suggesting that characteristics of those spaces were influencing the expression of these retiring behaviors; specifically, that both species of apes were more likely to retire in elevated locations in Exhibit A. While the exhibits are very similar, elements (e.g., number of visual barriers) may explain these differences and offer further insight in how exhibit design can influence the expression of natural behaviors in these species.