Meeting Abstract
Cetaceans are capable of extraordinary locomotor behaviors both in water and air. Whales and dolphins can execute aerial leaps by swimming rapidly to the surface of the water to achieve an escape velocity. Previous research on spinner dolphins demonstrated that this species was capable of leaping and completing multiple spins around their longitudinal axis with high angular velocities. This prior research suggested that the slender body morphology of spinner dolphins allowed for rapid spins in the air. The principals factors affecting the number of aerial spins a cetacean can execute are the moment of inertia of an individual and the use of control surfaces for subsurface corkscrewing, both of which are morphology-dependent. For typical individual spinner dolphins, Pacific striped dolphins, bottlenose dolphins, and humpback whales, each with swim speeds of 6 m/s, a speed close to their maximum, our model predicts that the number of aerial spins executable are 7, 2, 1.7, and 1.4, respectively, which are consistent with observations. These data imply that the rate of subsurface corkscrewing is limited to 2.7 rev/s for spinner dolphins, 2.0 for striped dolphins, and less than 1 rev/s for the bottlenose dolphins and humpback whales. The greater moments of inertia for the latter three species produce large torques on control surfaces that limit subsurface corkscrewing motion and aerial maneuvers.
