BEHAVIORAL REACTIONS OF HUMPBACK WHALES MEGAPTERA-NOVAEANGLIAE TO BIOPSY PROCEDURES

Accurate and precise descriptions of behavioral indicators of human activities which disturb cetaceans are required to better control adverse human impacts on these animals. We hypothesize that the application of a technique used to remove a small piece of innervated tissue, a biopsy darting procedure, is likely to result in the display of such behavioral indicators. In order to describe such displays, we recorded behavior of 22 humpback whales Megaptera novaeangliae before and after biopsy procedures in the southern Gulf of Maine. Reactions varied considerably among animals. Although respiratory responses were not consistent, biopsied whales generally decreased their ratio of surface to dive time and their net movement mte. Hard tail flicks occurred as an immediate reaction in approximately half the cases. Although 31 behaviors were tested for variation, only hard tail flicks significantly increased in either the number of animals that displayed them or the overall frequency of occurrence during postbiopsy reaction periods. While not statistically significant, some increase was noted in the frequency of trumpet blows and tail slashes, while slow swimming and apparent investigative behavior were noted to decrease. The strongest reactions, observed in two cases, occurred when the dart and retrieval line briefly snagged the whale's flukes. These findings complement and extend other studies on the response of baleen whales to human activity at sea.