WOODS HOLE, Mass. — When the whale known as Touché is hungry for a school of fatty fish, he circles below them, fashioning a net of air by streaming bubbles from his blowhole. Then he corkscrews toward the surface of the Gulf of Maine, herding the fish into an ever tighter packet with the bubbles and his 30-ton body. Finally he opens his jaw wide, takes a monstrous gulp and relaxes, breathing deeply at the water’s surface.

Then he dives again. Over and over.

Touché’s feeding strategy, captured in June by an electronic tag attached to his back, is of keen interest to scientists tracking North Atlantic humpback whales off Cape Cod.

“Every time we go out and put another tag on, we learn something else,” said Dave Wiley, research director of the Stellwagen Bank National Marine Sanctuary in Massachusetts, who returned to shore recently after plying its waters for two weeks with researchers from several institutions.

For Dr. Wiley, the most striking insight is that each humpback has its own set of behaviors, often confounding efforts to generalize about the species.