Behavioral responses to the zoo environment by white handed gibbons

Although there is a growing literature on the effects of zoo environments on nonhuman primate behavior, comparatively little research has been published on the behavioral responses of gibbons and siamangs (family: Hylobatidae) to zoo visitors. Here, we present the findings from our study on the effects of noise, visitor group size, and the presence of children on certain aspects of behavior in white handed gibbons (Hylobates lar) housed in two separate Canadian zoos. Observational data on various behaviors were obtained through selective focal animal sampling. These data were analyzed using Chi-square tests to estimate the effects of noise level, viewing group size, and the presence of children on behavior. The results of this analysis indicate that noise level and viewing group size often significantly affect behavioral responses, particularly with communicative behaviors such as looking at visitors, and open mouth display, as well as locomotive behaviors such as brachiating, hanging, and bipedal walking.