Play, Sexual Display, or Just Boredom Relief?

Abstract Cetaceans use objects and interact with conspecifics for play and socializing, often exhibiting complex behaviors that we do not understand. A few seconds of activity on the water’s surface rarely indicates intraspecific behaviors and interactions. What has already been described chiefly for common bottlenose dolphins ( Tursiops truncatus ) has been extrapolated to other species, with little information on river dolphins despite their accessibility. In this chapter, we review what is known about sexually related behaviors in different contexts, such as learning, play, sexual display, aggression, and boredom (weariness and restlessness through a lack of interest) among cetacean species, especially the Amazon river dolphin ( Inia geoffrensis ).