Is Enrichment Always Enriching and How Would You Know? Unintended Consequences and the Importance of Formal Assessment of Enrichment Programs in Bottlenose Dolphins (Tursiops truncatus)

Abstract

Bottlenose dolphins (Tursiops truncatus) are viewed as a highly intelligent species capable of complex behaviors. This requires marine parks to maintain dynamic environmental enrichment programs in order to ensure dolphins’ optimal psychological and physiological well-being while in human care. In this study, two experiments were conducted to determine the effects of different forms of enrichment on the behavior of four bottlenose dolphins. In Experiment 1, multiple forms of novel enrichment resulted in a shift away from individual swim patterns – a change that is associated with increased behavioral diversity and so often considered an improvement in animal welfare – but also resulted in avoidance behavior and initially resulted in a decrease in affiliative behavior. In Experiment 2, introducing choice of enrichments resulted in unintended social consequences, such as agonistic behaviors. These two experiments together demonstrated that interpreting the results of enrichment programs may not be as straightforward as often presumed. The results suggest that unique forms of enrichment and variable schedules might be particularly effective but also that consistent evaluation continues to be necessary to minimize unintended behavioral consequences