SAN FRANCISCO - Whale-watchers off the coast of San Francisco witnessed a once-in-a-lifetime act of nature when they saw a killer whale turn a great white shark into its prey.
The stunned whale-watchers gaped and whipped out their cameras as they saw the killer whale break the surface of the water holding a great white shark in its mouth.
The captain of the boat told National Geographic that the whale was holding the shark "like a cat with a mouse, just showing off".
The killer whale causes the shark to become immobile with a technique called "tonic immobility". It rams into the shark at high speed, stunning it. Then, it holds the overturned shark between its teeth until the shark dies from suffocation.
The whale then feasts on the dead shark.
Killer whales are intelligent creatures and can learn from each others. Therefore if one killer whale discovers this weakness in a shark, others in the same pod can learn the shark-killing technique by observation.
This then becomes a hunting technique that the killer whale pod uses. Evidence of this attack, which occurred in 1997, also shows that the great white shark is no longer at the top of the food chain, a popular belief held by marine biologists.
Mon, Feb 21, 2011
AsiaOne
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