Abstract # 13175 Event # 125:

Scheduled for Friday, August 10, 2018 11:45 AM-12:00 PM: (Chula Vista ) Oral Presentation


JAPANESE MACAQUE RANK IS A PREDICTOR OF DISPLACED AGGRESSION TOWARD HUMANS

J. M. Woods, S. R. Ross and K. A. Cronin
Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, 2001 N Clark St., Chicago, IL 60614, USA
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     The effect that visitors have on the behavior and welfare of animals is a widely-studied topic in zoo animal welfare. Typically, these studies focus on how the presence or activity levels of visitors affect the behavior of primates. However, for many species, and particularly primates, social rank can also have a large impact on behavior. Here, we considered the influence of both external (crowd size and activity levels) and internal factors (individual rank) on the occurrence of visitor-directed aggression by zoo-housed Japanese macaques (Macaca fuscata, N=12). We hypothesized that individual rank would predict the frequency of visitor-directed aggression with lower-ranking individuals more often redirecting aggression to visitors as safe targets. We conducted 52 weeks of observations (362.2 hours) on macaques living in a large, outdoor habitat and calculated rank weekly using the Elo-rating method, defined by sequences of interactions (Neumann et al., 2011, Animal Behaviour, 82, 911-921.). GLMM Full-null model comparisons indicated rank as a significant predictor of visitor-directed aggression (X2 = 29.4, p < 0.001), with lower-ranked individuals displaying more frequent aggression towards visitors. Additionally, visitor-directed aggression differed by crowd activity levels (p = 0.02), but not crowd size (p = 0.68). These results support our prediction that lower-ranking macaques redirect aggression toward zoo visitors, and emphasize the means by which intrinsic and extrinsic factors can combine to influence primate response to human presence.