Review of self-initiated behaviors of free-ranging cetaceans directed towards human swimmers and waders during open water encounters

Open water encounters of swimming and wading humans with wild cetaceans have increased worldwide. Behaviors being self-initiated by cetaceans during encounters and addressed towards humans still have received little study and their structure and function mostly remain unclear. This study reviews the scientific literature describing such behaviors. Unhabituated, habituated, lone and sociable and food-provisioned cetaceans from 10 odontocete and one mysticeti species were reported to show altogether 53 different behaviors which were affi liative (33 behaviors), aggressive/threatening (18) and sexual (2) in nature. Behaviors are listed in an ethogram. Due to varying research designs, observational biases cannot be excluded and comparability of results is sometimes hindered. Aggressive/threatening behaviors were reported mainly for food-provisioned and lone and sociable dolphins and these might be responses to inappropriate human behaviors. Sexual behaviors were only described for lone and sociable dolphins. Keywords: human–dolphin interactions; ethogram; swim-with-dolphin programs; whale watching