Biology: Dolphin Communication

BIOLOGY: DOLPHIN COMMUNICATION

The Complex Brain of the Dolphin

During the 1960s scientists began studying how the remarkable dolphin communicates. The dolphin is a mammal, not a fish, in the order Cetacea, which also includes whales. These mammals breathe with lungs, nurse their young, have extremely complex brains, and are otherwise similar to land mammals. In 1960 the neurophysiologist Dr. John C. Lilly reported on his four years of talking to bottle-nosed dolphins (Tursiops truncatas) at a U.S. Navy facility near Charlotte Amalie in the Virgin Islands. He implanted electrodes in the brains of thirty dolphins and found a "pleasure center": stimulating the electrode implanted there caused the dolphins to have wide eyes and look like they were smiling. They would also change their behavior to make Lilly stimulate the electrodes more often. Similar experiments had been performed on chimpanzees, and the dolphins learned much more quickly.

Sending a Distress Signal

Lilly also put a partly paralyzed dolphin in a pool with other dolphins. The paralyzed dolphin could not reach the surface to breathe, and so it would die without help. Other dolphins learned of their new neighbor's distress and helped him reach the surface and stay there, talking to each other in frequencies above the range of human hearing. When Lilly played back the tape of their talking, at one-quarter speed, he could hear the "mayday" call given by the paralyzed dolphin. When Lilly played the tape back to other dolphins, they reacted to the call.

A Language of Their Own

Other experiments involved Lilly's talking to the mammals. They seemed to repeat his words in high, squeaky voices. Dr. Sidney Galler, director of the Naval Researches Biological Branch, has claimed that dolphins communicate with each other in a language of their own, using sonar and special chemical-sensing organs.

Sources:

Daniel Cohen, "Dolphin: Smarty of the Sea," Science Digest, 48 (December 1960): 43-47;

"Dolphin Talk," Time, 75 (4 January 1960): 53-54;

W. S. Griswold, "The Case of the Blindfolded Dolphin," Popular Science, 177 (August 1960): 70-73, 184.