Monday, August 3, 2009
At 20+ feet and 4,500 pounds, one would think the great white shark is a clumsy killer, relying on brute force to hunt. Instead, with acute color vision, the largest scent-detecting organs of any shark, and sensitive electroreceptors it senses environmental cues beyond human experience. Using optimal foraging theory, scientists think that great whites are extremely picky eaters, usually rejecting low-fat prey to maximize every hunt - getting the maximum bang for each bite. This explains why great whites readily attack seals, but avoid penguins and seagulls. Most great whites attack during high tide, where seals enter and exit the water. Relying on stealth, great whites attack from the deep and usually within 2 hours of sunrise.
What about attacks on humans? Are we, like seals, a favorite for sharks? People are surprised to learn that sharks really don't like to eat humans. Of the few attacks that do occur, 85% of victims survive, and there is almost no case of a shark wholly consuming a human.
OH, almost forgot - here's an amazing video of a great white literally jumping out of the water to attack a seal.