Meeting Abstract
Locomotion and feeding are integrated in many aquatic vertebrates, and the behavioral plasticity of these connected systems may reflect broad-scale functional and evolutionary responses to ecological dynamics. Predator-prey interactions may require the optimization of, or sufficient performance in, maneuverability, coordination, and prey capture speed. We used video and movement sensor tags to quantify the body and skull kinematics during feeding events in rorqual whales, a family of baleen whales that exhibit an extreme lunge filter feeding mechanism. Lunge feeding consists of an acceleration to high speed and engulfment of a large volume of prey-laden water, however, despite previous assumptions the kinematics of lunge feeding were not conserved. While krill-feeding blue and humpback whales exhibited temporally distinct acceleration and engulfment phases, humpback whales pursuing more agile prey (i.e. anchovies) demonstrated highly variable coordination of skull and body kinematics in the context of complex prey-herding techniques. Despite pursuing faster prey, fish-feeding humpbacks often fed at slower speeds than krill-feeding humpbacks. Escape response experiments on anchovies startled by a looming stimulus parameterized with tag data suggest that whale speed has less of an effect on prey escape responses than the timing of the mouth opening and the rapid increase in projected body area. Our results have important implications for understanding the mechanisms and behavioral strategies large predators use to capture different prey. Moreover, these studies help inform the dynamics that govern energy flux through filter feeders in coastal upwelling ecosystems.
