Scaling of oscillatory kinematics and Froude efficiency in baleen whales
Abstract
High efficiency lunate-tail swimming with high-aspect-ratio lifting surfaces has evolved in many vertebrate lineages, from fish to cetaceans. Baleen whales (Mysticeti) are the largest swimming animals that exhibit this locomotor strategy, and present an ideal study system to examine how morphology and the kinematics of swimming scale to the largest body sizes. We used data from whale-borne inertial sensors coupled with morphometric measurements from aerial drones to calculate the hydrodynamic performance of oscillatory swimming in six baleen whale species ranging in body length from 5 to 25 m (fin whale, Balaenoptera physalus; Bryde's whale, Balaenoptera edeni; sei whale, Balaenoptera borealis; Antarctic minke whale, Balaenoptera bonaerensis; humpback whale, Megaptera novaeangliae; and blue whale, Balaenoptera musculus). We found that mass-specific thrust increased with both swimming speed and body size. Froude efficiency, defined as the ratio of useful power output to the rate of energy input ( Sloop, 1978), generally increased with swimming speed but decreased on average with increasing body size. This finding is contrary to previous results in smaller animals, where Froude efficiency increased with body size. Although our empirically parameterized estimates for swimming baleen whale drag were higher than those of a simple gliding model, oscillatory locomotion at this scale exhibits generally high Froude efficiency as in other adept swimmers. Our results quantify the fine-scale kinematics and estimate the hydrodynamics of routine and energetically expensive swimming modes at the largest scale.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 01, 2021
- Source ID
- 10.1242/jeb.237586
Entities
People
- Andrew Stanworth
- Caroline R Weir
- David E. Cade
- Frank E Fish
- Hayden J. Smith
- Jacopo Di Clemente
- Jean Potvin
- Jeremy A. Goldbogen
- John Kennedy
- K C Bierlich
- Matthew Savoca
- Max Czapanskiy
- Paolo S Segre
- William Gough
Organizations
- Duke University
- Falklands Conservation
- National Science Foundation
- Office of Naval Research
- PADI Foundation
- Saint Louis University
- Society for Marine Mammalogy
- Southwestern University
- Stanford University
- University of California, Santa Cruz
- University of Copenhagen
- West Chester University of Pennsylvania
- World Wide Fund for Nature