Meeting Abstract
Biologging approaches to study the biology of free-ranging animals have focused on either movement or video, but rarely are these two data sets integrated. We developed a tag system to measure the fine-scale kinematics of cetaceans while simultaneously recording video from dual cameras. The movement sensors included a pressure transducer, tri-axial inertial sensors (accelerometers, magnetometers, gyroscopes), and a paddle-wheel speed sensor. The cameras were pointed anteriorly 45 degrees to the right and left of the long axis of the tag, together generating a 180-degree view in the horizontal plane. We deployed these tags on 5 blue whales and 8 humpback whales off the coast of California in the summer of 2014. For the first time, we observed a wide-range of behaviors of the tagged whale, conspecifics, and parasites. These included interactions between whale lice, aggregations of prey (krill, anchovies) and non-prey (siphonophores) species, remora swimming and attachment behaviors, echelon swimming of conspecifics, and cooperative feeding with both whales and sea lions. We also observed how the movements of flippers and flukes were involved in facilitating different maneuvers, including lunge feeding. When the tags were pointed perpendicularly to the long axis of the whale’s body, we could detect simultaneous movement of flipper and fluke, highlighting the fine-scale body control and varied use of different propulsion and control surfaces. By combining video and kinematic data, this tag design serves as an important tool for understanding the biomechanics and behavioral ecology of large aquatic vertebrates.
