Abstract:

Odontocete echolocation studies reveal a system with both great plasticity and precision, but knowledge of the animal's day-to-day use of the process is limited. High-speed cine photographs of a trained bottlenose dolphin swimming underwater show that the dolphin's head and rostrum move vertically even when the dolphin swims at modest speed. Does this movement limit or otherwise affect the echolocation precision of freely-swimming dolphins? Results from kinematic studies, combined with echolocation system descriptions from acoustic research, were examined to show if head movements might limit acoustic abilities of swimming dolphins. So far, these speculative approaches are inconclusive. The general synthesis, using disparate data from acoustic and kinematic studies, indicates that head motion associated with modest swimming speed does not degrade echolocation ability. Data from coordinated studies that involve both echolocation and movement at realistic, natural speeds are lacking. Given the difficulty involved in working with naturally swimming dolphins, this data set is likely to remain unfilled, so further conclusions will also remain speculative.