Previous studies have shown that the number, noise level, and activity level of zoo visitors can negatively influence the behavior of captive animals. This study combined these three factors into a single visitor impact score and assessed whether visitor impact predicted the frequency or occurrence of displacement activities, affiliative behaviors, and aggression in a group of six captive ebony langurs (Trachypithecus auratus). This study also examined whether the amount of time the ebony langurs spent sleeping each day was correlated to the mean visitor impact score for that day. We used negative binomial and binomial models to analyze data collected during 5-min focal follows. Higher visitor impact scores predicted greater expression of displacement activities, affiliative behaviors, and aggression, suggesting that zoo visitors were a source autonomic arousal for the langurs. Similarly, the langurs spent more time sleeping on days with higher mean visitor impact scores, which may indicate learned helplessness. This study suggests that zoo visitors may be a source of environmental stress for captive ebony langurs. Nevertheless, the positive relationship between high visitor impact score and the occurrence of affiliative behavior types may indicate that the langurs use certain activities to decrease visitor-induced stress.

中文翻译：

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动物园游客会影响圈养乌木叶猴（Trachypithecus auratus）的睡眠，移位活动以及从属和攻击行为

先前的研究表明，动物园游客的数量，噪音水平和活动水平可能会对圈养动物的行为产生负面影响。这项研究将这三个因素合并为一个访客影响分数，并评估了访客影响是否预测了六只圈养乌木叶猴（Trachypithecus auratus）的位移活动，亲和行为和攻击的频率或发生情况）。这项研究还检查了乌木叶猴每天睡觉的时间是否与该天的平均访客影响评分相关。我们使用负二项式和二项式模型来分析在5分钟的焦点跟踪过程中收集的数据。较高的访客影响得分预示着位移活动，联结行为和侵略性的更多表达，这表明动物园访客是叶猴的自主神经激发。同样，叶猴在平均访客影响得分较高的日子里，会花更多时间睡觉，这可能表明学习无助。这项研究表明，动物园游客可能是圈养乌木叶猴的环境压力来源。不过，