Meeting Abstract
Maneuverability, defined generally as the ability to change speed and direction, is critical to survival. Rorqual whales, the world’s largest vertebrates, survive by catching much smaller and more maneuverable prey. They do so by using a series of surprisingly acrobatic maneuvers to approach schools of small fish or krill, accelerating, and engulfing large mouthfuls of prey-laden water. It has been thought that organisms that use lift based propulsion are constrained by the differential scaling of lift producing surfaces and body volume, but this has not been comprehensively tested in free-swimming animals. Rorqual whales exhibit a large range of sizes and have substantial differences in the morphology of body shape and propulsive surfaces, which makes them excellent subjects for studying the scaling of maneuvering performance at the upper extremes of body size. Using a collection of data from suction-cup attached, bio-logging tags equipped with a suite of inertial sensors (6 species, 384 deployments), we developed a framework to comprehensively quantify and compare the maneuvering performance of free-swimming whales. We identified five simple rotational and translational maneuvers (rolls, upward pitch changes, downward pitch changes, yawing turns, accelerations) that are effected by different hydrodynamic controls and can be sequentially pieced together to build complex trajectories used for capturing prey. Each type of maneuver is stereotypical, repeatable, and used thousands of times during the course of a multi-hour deployment, and thus can be automatically detected using a targeted search sequence. Taken together, an analysis of the performance limits of these five simple maneuvers and an analysis of how simple maneuvers are sequentially used to perform complex behaviors will allow us to quantify the overall maneuvering performance within and across species of rorqual whales.
