Meeting Abstract
Breaching is one of the most iconic behaviors among aquatic vertebrates, yet fundamental questions remain unanswered regarding how and why these maneuvers are performed. In addition to being a spectacular biomechanical event, breaching may have important implications for many physiological and behavioral processes. Breaching in baleen whales is hypothesized to occur for several reasons: parasite removal (e.g. barnacles and remoras), as a communicative social behavior, or it may simply be enjoyable for the animals. Because breaching often involves a full departure of a large body from the sea surface, the kinematics leading up to and during the breach may be an important test of maximum locomotor performance. In order to quantify the kinematics of this behavior, we analyzed multi-sensor and video data from suction-cup tags attached to humpback whales (Megaptera novaeangliae) that breached. First, we assessed the stereotypy of breaching behavior among tagged individuals (adults and one calf) by analyzing changes in depth, body orientation (pitch, roll, yaw), velocity, and fluke stroke rate. We integrated these kinematic data with estimated morphological data into a mathematical model of ballistic trajectory to predict maximum breaching height as a function of animal velocity and mass. Using this predictive model, we estimated the energetic demands for a given breaching event and compared those values to other high performance maneuvers, such as lunge feeding. Lastly, we extended our model to the upper limits of body mass observed in baleen whales to explore the physical limits of breaching.
