Great white sharks identify a location from which to strike, and then search the surrounding killing zone for their next victim. Scientists observing hundreds of great white attacks on fur seals off South Africa have discovered that sharks use a premeditated hunting strategy
The researchers observed 340 attacks by great whites on fur seals within 2km of Seal Island, in False Bay, South Africa. After each attack, the scientists recorded the precise geographical location and the depth of the water, as well as whether the attack was successful or not.
By applying these analytical techniques used by law enforcement in geographical profiling of criminal acts, including those by terrorists and serial killers., the researchers established that great white sharks also follow a similar hunting strategy.
The largest most dominant sharks would regularly pick a particular anchor point, and search for their next victim close to this location. Most large sharks regularly returned to a spot some 100m due south of the main place where seals came ashore on to the island.
The anchor point did not itself provide the shark with the best chance of intercepting a seal. But the location did provide an optimal balance between detecting prey and capturing it.
Smaller sharks seem to avoid competition with larger ones by widening their search strategy. But they also tend to be less successful, suggesting that great white sharks learn through experience which are the best hunting sites.
"White sharks, like other predators, may refine their search patterns with experience," the researchers write in the Journal of Zoology, published by the Zoological Society of London.