Document Type


Date of Degree Completion

Spring 2019

Degree Name

Master of Science (MS)


Primate Behavior

Committee Chair

Lori K. Sheeran

Second Committee Member

Kara Gabriel

Third Committee Member

Gabriella Skollar


Anthropogenic stress can negatively impact the health of captive animals. Visitors may be a source of stress to captive animals in zoos and sanctuaries. Javan gibbons (Hylobates moloch) are endangered, and healthy captive populations are important to the species’ conservation. The purpose of this study is to assess the impact of visitor presence on the activity budgets of captive Javan gibbons. Using continuous sampling, I recorded the activity budgets of 10 Javan gibbons housed at the Gibbon Conservation Center (GCC) in Santa Clarita, California. I collected data in the mornings, middays, and afternoons on visitor days and non-visitor days. I conducted factor analysis to identify four behavioral categories and five behaviors that did not fit into a category. I then conducted factorial analyses of variance (ANOVAs) to determine the effects of time period and visitor presence on the duration of each behavioral category and uncategorized behavior for each gibbon. ANOVAs revealed time of day has a stronger effect than visitor presence on gibbon activity budgets. Individuals varied in their behavioral response to time of day and visitor presence. Main effects of visitor condition were minimal, though there were several interaction effects between time of day and visitor condition. These results indicate further visitor effects research should take time of day into account, and caregivers should make visitor policy decisions based on the individual animals in their care. Furthermore, interaction effects suggest captive gibbons benefit from having days when there are no visitors so as to recover from possible visitor effects.



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