Tactile Behavior in a Group of Captive Rough-Toothed Dolphins as a Function of Opportunities to Play with Objects

Cetaceans live in complex physical and social environments that are frequently changing. In contrast, the captive environment for marine mammals is often lacking in stimulation. As a result, enrichment is often used to increase species-typical behaviors and enhance the well-being of the animals. The purpose of this study was to compare the effects of enrichment objects on the social behavior of a group of seven captive rough-toothed dolphins (Steno bredanensis). Observations of this species in the wild suggest it may have a particular affinity for tactile and object play behaviors. Therefore, these behavior categories were a primary focus during this investigation. The effect of enrichment on the social behavior of the subjects was assessed by comparing two conditions, the no enrichment condition and the enriched condition. The behaviors of interest were coded and analyzed from focal follow video recordings for each dolphin collected over 28 trials. The results revealed a significant increase in the total number of behaviors engaged in by the dolphins when enrichment objects were present. Furthermore, aggressive social behaviors were significantly reduced during the enriched condition. These findings demonstrate that enrichment can increase species-typical behaviors of rough-toothed dolphins as well as minimize aggression. The implications of these results for the welfare of dolphins in human care and how they might compliment studies with wild populations are discussed