Study sheds new light on dolphin coordination during...( CORVALLIS Ore. Spinner dolphins hav...)

CORVALLIS, Ore. Spinner dolphins have long been known for their teamwork in capturing prey but a new study using high-tech acoustics has found that their synchronization is even more complex than scientists realized and likely evolved as a strategy to maximize their energy intake.

The study, by scientists at Oregon State University and the University of Hawaii, found that dolphins engage in a highly choreographed night-time "dance" to enclose their prey, and then dart into the circle of confused fish in organized pairs to feed for about 15 seconds, before backing out and letting the next pairs in line take their turn.

Results of the study were published this week in the journal, Acoustical Society of America.

"Synchronized swimmers have nothing on spinner dolphins," said Kelly Benoit-Bird, a marine ecologist at Oregon State University and lead author on the study. "The degree of synchrony they display when feeding is incredible especially considering that they're doing it at night, several meters below the surface where they can't see their prey or each other."

The study is important, scientists say, because it greatly expands knowledge of spinner dolphin behavior and it opens up new fields of scientific inquiry into underwater ecosystems made possible by technological advancements in acoustical monitoring. It was funded by the National Science Foundation and the Office of Naval Research.

Much of the knowledge about spinner dolphin feeding has been anecdotal because they are primarily nocturnal in their feeding, Benoit-Bird pointed out. However, acoustical eavesdropping allowed the scientists to "view" the dolphins' behavior without interrupting their routine with lights and underwater cameras. In their study off the coast of Oahu, Hawaii, the scientists used sonar readings from a "multi-beam echo-sounder" to monitor groups of spinner dolphins. The animals' systematic approach to feeding was eye-opening.'/>"/>