Hydrodynamic properties of fin whale flippers predict maximum rolling performance
Segre, P. S., Cade, D. E., Fish, F. E., Potvin, J., Allen, A. N., Calambokidis, J., Friedlaender, A. S., Goldbogen, J. A. . 2016 September. Hydrodynamic properties of fin whale flippers predict maximum rolling performance. Journal of Experimental Biology. DOI: 10.1242/jeb.137091
Maneuverability is one of the most important and least understood aspects of animal locomotion. The hydrofoil-like flippers of cetaceans are thought to function as control surfaces that effect maneuvers, but quantitative tests of this hypothesis have been lacking. Here we construct a simple hydrodynamic model to predict the longitudinal-axis roll performance of fin whales, and we test its predictions against kinematic data recorded by onboard movement sensors from 27 free-swimming fin whales. We found that for a given swimming speed and roll excursion, the roll velocity of fin whales calculated from our field data agrees well with that predicted by our hydrodynamic model. Although fluke and body torsion may further influence performance, our results indicate that lift generated by the flippers is sufficient to drive most of the longitudinal-axis rolls used by fin whales for feeding and maneuvering.