- The Washington Times - Monday, June 22, 2009

They don’t attack at random but stalk specific victims, lurking out of sight.

The sharks hang back and observe from a not-too-close, not-too-far base, hunt strategically and learn from previous attempts, according to a study being published online Monday in the Journal of Zoology. Researchers used a serial-killer-profiling method to figure out how the fearsome ocean predator hunts, something that’s been hard to observe beneath the surface.

“There’s some strategy going on,” said study co-author Neil Hammerschlag, a shark researcher at the University of Miami who observed 340 great-white-shark attacks on seals off an island in South Africa. “It’s more than sharks lurking at the water waiting to go after them.”

The sharks feeding at Seal Island could have just hovered right where the seals congregated if they were random killers-of-opportunity, Mr. Hammerschlag said. But they weren’t.

The sharks had a distinct MO.

They were focused. They stalked from a usual base of operations, 100 yards from their victims. At that distance, they were close enough to see their prey, but not so close that they could be seen and scare off their victims. They attacked when the lights were low. They liked their victims young and alone. They tried to attack when no other sharks were around to compete. They learned from previous kills.

And they attacked from below, unseen.

There’s a big difference between great white sharks and serial killers, and it comes down to that old gumshoe standard: motive. The great whites attack to eat and survive, not for thrills. And great whites are majestic creatures that should be saved, Mr. Hammerschlag said.

Mr. Hammerschlag and R. Aidan Martin, the late Canadian shark researcher, watched sharks from sunrise to sunset, applied the “fancy math” of geographic profiling and came out with plots that showed there was some real stalking going on, Mr. Hammerschlag said. Older sharks did better and were more stealthy than younger, smaller sharks, demonstrating that learning was occurring, he said.

The study focused on just one location, but the same principles are likely to be applied to other shark hunting grounds. However, they can’t really apply to shark attacks on people because those are so infrequent, Mr. Hammerschlag said. But if you could figure out the base of operations for the great whites, it would give you a good idea of places to avoid if you were worried about shark attacks, he said.

Other animals, such as lions, also reveal strategies in their hunting, Mr. Hammerschlag said. Land animals have been observed more easily from the air or elsewhere on the ground.

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