Heptuna: The most outstanding subject

Abstract

One of the best experimental collaborators I have ever worked with was HEP, a bottlenose dolphin (Tursiops truncatus). HEP was instrumental in leading the way for subsequent dolphin investigations. In the first study on dolphin sound localization, HEP was the willing subject [D. L. Renaud and A. N. Popper, “Sound localization by the bottlenose porpoise Tursiops truncatus,” J. Exp. Biol. 63, 569–585(1975)]. Thus began a series of critical experiments that set the foundations of cetacean hearing and echolocation. I had the pleasure to partner with Whit Au and HEP to explore the many aspects of dolphin hearing and echolocation. HEP carried the experience of his training and testing to new experiments. If he saw just one response manipulandum, he seemed to know it was a go/no go response requirement, or if two, a forced choice response. HEP was the first animal to use “jaw phones” to test hearing, and interaural time and intensity differences. He demonstrated he could control his echolocation clicks, he provided measures of his transmitting and receiving beam patterns, and much more. Unfortunately, we lost HEP in 2010 after a 40-year history with the U.S. Navy Marine Mammal Program.