Behavior reference intervals and activity budgets of bottlenose dolphins in accredited zoos and aquariums

Knowledge of the spectrum and frequency of species-appropriate behaviors is valuable when evaluating the welfare of animals living under professional care. Dolphins have a rich behavioral repertoire and behavioral metrics have been used to quantify behavior. Data in the present study were collected as part of a larger study titled “Towards understanding the welfare of cetaceans in zoos and aquariums” (colloquially called the Cetacean Welfare Study). Behavior data were collected on 43 common bottlenose dolphins (Tursiops truncatus) at 23 facilities. Dolphins were video recorded three times per week for 25 min over one five-week data collection period between July and November of 2018 and a second five-week data collection period between January and April of 2019. Solo and group swimming were the two most common behavior states for dolphins. Group active, chase, fast swimming, tactile, and ventral swimming were significantly impacted by age. Interacting with conspecifics was significantly impacted by time of day. The rate of fluke-out dives was associated with sex. Behavioral diversity was significantly impacted by age and sex. The findings presented here are representative of behavioral observations collected from the largest number of individuals in the largest number of zoo and aquarium habitats that have been published to date. These results provide the first normal reference intervals for behavior and a comprehensive activity budget that encompasses the behavior of dolphins living in a variety of accredited zoo and aquarium habitat types and social structures. The activity budgets and reference intervals are valuable as a tool for monitoring welfare and for increasing our understanding of typical dolphin behavior across broad environmental and management conditions. •Activity budgets and reference intervals for bottlenose dolphins were generated.•Solo and group swimming were the two most common behavioral states.•Social behaviors were most related to age compared to other variables.•Reference intervals can be used alongside intra-individual data to assess welfare.