Verification of the effectiveness of environmental enrichment and the influence by visitors in captive tigers

Abstract

Zoo animals are often bred in environments that are significantly different from their natural habitats. As a result, abnormal behaviors, such as pacing and low diversity in the behavior repertoire, are problematic. These aspects are particularly noted in captive large felid species, such as tigers. To alleviate these problems, environmental enrichment is being conducted in many zoos. With pacing behavior, several factors are involved, including the presence or absence of enrichment and the influence of visitors, but such factors have rarely been investigated simultaneously. In the present study, we investigated the effectiveness of enrichment and the factors influencing the behavior of captive Amur tigers (Panthera tigris altaica).

We observed the behavior of 3 Amur tigers in the Kyoto city Zoo and examined the effect on behavior of types of enrichment, temperature, and number of visitors. The tigers’ behavior was directly observed and recorded using scan sampling every 3 minutes, for 2 hours each, in the morning and afternoon between June and November 2017. In addition to behavior, the maximum temperature, the number of visitors, and the types of enrichment were also recorded. When the greatest variety of enrichments was installed, pacing frequency of the tigers decreased significantly (P < 0.05), and the use frequency of the enrichments increased significantly (P < 0.01). High maximum temperatures significantly decreased the frequency of pacing and enrichment usage, and a significant increase in resting behavior was observed as temperatures rose. The presence of visitors did not affect pacing behavior but decreased tiger activity levels. Results suggest that installation of multiple enrichment features is effective for suppressing pacing in tigers and is useful for stimulating behaviors, including exploration and predatory behavior. Also environmental factors such as temperature and the presence of zoo visitors were thought to affect tigers’ behavior.