Diving into the MYSTERIOUS WORLD of DOLPHINS

Ask, Mar 2008 by Rahm, Linda

"When a group of dolphins approaches me, at first I only hear many overlapping voices and noises. Then, sometimes, several living torpedoes come zooming at me as they twist and curl around one another. They squawk, whistle, and click at one another. They face off, head to head, jaws flashing and huge bubbles coming from their blowholes. It's like attending a huge rock concert with people shouting and screaming all around you."

-Kathleen Dudzinski

As a girl, marine biologist Dr. Kathleen Dudzinski felt a passion for the ocean and loved animals and science. Now she is fulfilling a lifelong dream. She studies dolphins in the wild, learning how these intelligent creatures maneuver and communicate in their mysterious world of water and sound.

Like people, dolphins have large brains compared to the size of their bodies, and they seem to communicate using sounds-whistles, chirps, squeaks, and clicks. Each dolphin even has a "signature whistle" that is like a name because it belongs to only one dolphin.

When they hunt, dolphins work together to herd the fish. Some leap out of the water, making a slapping sound on the surface, and there is constant chatter and vocalization. Are vocalizing dolphins directing other dolphins how to hunt? Are they telling each other when it's their turn to feed?

To try to answer such questions, Dudzinski enters the dolphins' underwater world, recording and analyzing their sounds and observing their behavior. Sometimes she uses a motorized scooter to swim along with the dolphin group, or pod. Although she wonders how dolphins know when to change direction, she's learned how to turn with the pod and occasionally takes the lead herself while the dolphins follow.

Learning about dolphin communication is difficult and requires special equipment. Dolphins don't open their mouths when they make their clicks, so it's hard to know who's talking. It's equally hard to know who's listening-which of the other dolphins are receiving the sounds and being "spoken to."

Dudxinski has designed special audiovisual equipment with stereo hydrophones (underwater microphones) that help her detect which dolphin is speaking when she later watches the video of her dive. And she uses a computer that enables her to analyze the sound-wave patterns different dolphins make.

This equipment helps her understand how dolphins use sound together with behavior to communicate. For instance, dolphins sometimes touch fins while making a series of clicks. Dudzinski thinks this may be like shaking hands.

It takes courage and strength to track dolphins in open water. It also requires a lot of patience, since hours can be spent finding the dolphins. When diving, Dudzinski observes a single dolphin for as long as she can, to become familiar with its behavior pattern. She has also been successful in collecting data by following dolphin groups over a period of years.

Dudzinski hopes one day to learn whether dolphins-who seem to be able to understand some human language-have their own language that they use in the wild. And if they do, what kinds of things are they saying to one another? But it's a long-term project. While dolphins are like humans in some ways, how they use sound to communicate in their watery world is still mysterious to us. "It's like trying to put together a giant jigsaw puzzle when you've lost the box lid with the puzzle's picture on it," Kathleen Dudzinski says.