Humpback Whale (Megaptera novaeangliae) Communication: The Context and Potential Functions of Pec-Slapping Behavior on the Hawaiian Wintering Grounds

Abstract

Humpback whales display a variety of percussive behaviors that may function as communication between conspecifics. Pectoral-fin slapping behavior is commonly observed in a variety of marine mammals including seals, dolphins, and humpback whales. Data from 5-years of behavioral observations of humpback whales on the Hawaiian wintering grounds were compiled and analyzed. Overall findings suggest pec-slapping behavior is dependent on the performer's age class, sex, and social role. Adult females appear to pec-slap in competition groups in efforts to encourage competition from surrounding males, indicating her readiness to mate. Adult males pec-slap while disaffiliating from other males, possibly in attempts to maintain a non-agonistic male association. Subadult pee slapping is likely a form of "play", an important characteristic in the development, coordination, and learning in young mammals. These discoveries can serve as tools to enhance the interpretation of humpback whale social behavior, and provide a model for understanding other percussive behaviors.