Functional hearing groups among marine carnivores

Paul Nachtigall’s pioneering research on hearing and echolocation has been fundamental to our present understanding of functional hearing groups in fully aquatic marine mammals. His application of high-resolution psychophysical methods with trained subjects, his role in the development of technologies to measure and interpret auditory evolved potentials, and his syntheses of hearing, echolocation, and cognition have revealed the traits that differentiate and aggregate cetaceans on the basis of their acoustic sensitivity. Along the way, he has fostered collaborations and sharing of information that has had an enduring impact for the management and conservation of marine mammals. In the last decades, understanding of hearing abilities in marine carnivores has also advanced, with research motivated by sustained concern for human-generated noise in marine environments. Studies of a few representative pinnipeds obtained with classic behavioral methods have grown to include hearing assessments for many additional taxa including northern and southern true seals, sea lions, walrus, sea otters, and even polar bears. This talk reviews our growing understanding of functional hearing groups among the marine carnivores, inspired by the comparative framework established by Nachtigall and others for echolocating marine mammals.