The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)

Anticipatory behavior in captive male western lowland gorillas (Gorilla gorilla gorilla)


1Primate Osteology Lab, Department of Anthropology, University of Oregon, 2Department of Zoology, Michigan State University, 3Population Sustainability Team, San Diego Zoo Institute for Conservation Research

April 18, 2020 , Platinum Ballroom Add to calendar

The primary goal of this study was to explore behaviors considered undesirable in captive populations of western lowland gorillas (Gorilla gorilla gorilla). We were particularly interested in anticipatory behaviors surrounding the end-of-day transition into off-exhibit holding and the impact of this anticipation on social proximity and space use. Subjects were three male gorillas in the San Diego Zoo troop and two males in the San Diego Zoo Safari Park troop. We conducted 124.5 hours of live behavioral observations over a six-week period between June 11 and July 20, 2018, using the Behavioral Observation Research Interactive Software (BORIS) Application. We used continuous sampling to record behavior, social proximity, and location within the exhibit. We used ANOVAs to test differences in behavioral rates between individuals, and regressions to test linear correlations with time. Two of the focal males showed an increase in self-grooming throughout the day (F-test=7.59, p<0.01; F-test=8.26, p<0.01), three of the focal males showed increased spatial selectivity (F-test=84.97, p<0.0001; F-test=12.79, p<0.001; F-test=10.58, p<0.01), and one male increased his rate of aggressive events as time progressed (F-test=8.38, p<0.01). Overall, all five focal animals demonstrated a significant change in undesirable behavior as the time to transition to off-exhibit holding approached. Introducing new husbandry practices that foster predictability, such as reliable auditory cues during nightly recall, may be useful in mitigating undesirable anticipatory behaviors, but further research is necessary.

This study was funded by Patricia Beckman and the J.W. Sefton Foundation as part of a summer research fellowship at the San Diego Zoo Institute for Conservation Research.

Slides/Poster (pdf)