When is enrichment enriching? Effective enrichment and unintended consequences in bottlenose dolphins (Tursiops truncatus)

Bottlenose dolphins (Tursiops truncatus) are viewed as a highly intelligent species, capable of complex behaviors, requiring marine parks to maintain dynamic environmental enrichment procedures in order to ensure their optimal psychological and physiological well-being in human care. In this study, two experiments were conducted to determine the effects of different forms of enrichment on the behavior of bottlenose dolphins. In Experiment 1, the most successful enrichment included highly novel items, which resulted in avoidance, but also what is frequently considered positive behavioral changes including a reduction in circle swimming and an increase in social behavior. In Experiment 2, the use of choice resulted in negative unintended social consequences. These two experiments together demonstrate that the results of deploying enrichment may not be as clear-cut as previously presumed. In order to maintain positive benefits of enrichment, the results of this study suggest that unique forms of enrichment should be implemented on a variable schedule that is offered several times a year and consistently evaluated for effectiveness.