When sperm whales talk, Michael Dougherty listens.

Not only that, the University of Washington researcher and electrical engineering doctoral student can recognize the voice and tell you exactly which whale is speaking.

Dougherty has developed a method of acoustic analysis that allows him to identify individual sperm whales by the sounds they emit. The technology, which performed with nearly 100 percent accuracy during a pilot study on a limited number of whales, is believed to be the first of its kind. It promises to help researchers better understand how the leviathans interact as individuals and groups. It could also be an efficient means of tracking the movements of one of the ocean's more elusive mammals.

"It worked even better than we had hoped during our pilot study," Dougherty said. "I think biologists who study the whales will find it very useful after we develop it into a field-deployable technology."

Sperm whales are probably best known to the public through Herman Melville's novel Moby Dick. Just as the whale in that story was hard to find, so can sperm whales be difficult to keep tabs on in real life. When studying other marine mammals, researchers typically use photography to identify individuals, making distinctions on the basis of such characteristics as marks and coloring or notches and irregularities on dorsal fins or tails.

That method is less effective with sperm whales.

"Whereas other species, such as orcas, will swim together, sperm whales tend to spread out," Dougherty explained. "They may be a kilometer or more apart. They're certainly in acoustic contact with one another, but you can't keep track of who's where with just a camera."

To compound the problem, sperm whales tend to be out of sight more often than not. They are considered among the deepest diving of the whales, descending thousands of meters in a single dive and staying submerged for as long as two hours at a time.

"They spend most of t
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Contact: Rob Harrill
rharrill@u.washington.edu
206-543-2580
University of Washington
28-Oct-1999