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Top Five Reasons We Think Sharks Are Intelligent

Are Sharks Intelligent?

Shark intelligence is difficult to measure. We can’t give sharks an IQ test or probe them with questions. We can only get a glimpse into their minds by observing their behavior. Here are five reasons why scientists think sharks learn and problem solve rather than simply coasting by on pure instinct.

5 SHARKS ARE STRATEGIC HUNTERS

Great white sharks have learned to use different hunting strategies for different prey. At Mexico’s Guadalupe Island, white sharks have learned to attack giant elephant seals from the rear to avoid their sharp canines, and to retreat while their prey bleeds out to avoid a struggle. But when attacking smaller harbor seals, they simply pluck them from the surface and drag them down until they suffocate.

4 SHARKS LEARN FROM THEIR MISTAKES

Great whites aren’t born knowing how to hunt seals. They have to learn. At South Africa’s Dyer Island, young great whites are often seen clumsily attacking their prey, and usually missing. After years of practice, they eventually “graduate” to hunting at nearby Seal Island, where old veterans like Colossus have a 48% success rate when attacking seals at the surface. Sharks don’t give up; they learn through trial and error.

3 SHARKS SOCIALIZE WITH ONE ANOTHER

Competition for prey can be fierce, so white sharks have worked out a clever social ranking system to avoid costly fighting. Specific behaviors like circling, fin flapping and tail thrashing are some of the ways that white sharks have learned to establish dominance or contest kills without resorting to violence.

2 SHARKS ARE CURIOUS, PERHAPS EVEN PLAYFUL

Sharks are curious creatures. They commonly approach divers and boats to investigate in a non-threatening way. Sharks mouth or take test bites of potential prey to get a better sense of what they are; in fact, most sharks attacks are simply test bites. Sharks may also play; porbeagles seemingly playing with kelp and driftwood, and great whites have been observed tossing live seals repeatedly into the air.

1 SHARKS WORK TOGETHER

While we think of sharks as solitary creatures, they do occasionally band together. Sevengill sharks work together to encircle their prey; one will play decoy while another attacks from behind. Whale biologist Peter Best reported seeing a group of white sharks working together to move the carcass of a beached whale into deeper water so that they could more easily feed on it, suggesting they also understand the basics of flotation.

Sharkopedia : Are Sharks Smart? |

Trained Sharks At the Shedd Shatter Stereotypes

Aquarists at the Shedd Aquarium in Chicago conditioned sharks over a ten-year period to respond in specific ways to specific cues, proving that sharks can be trained just like whales and dolphins.

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Did You Know?

Shark Brains Aren't Really The Size of a Walnut

The idea that a great white’s brain is the size of a walnut is a common misconception. It’s based on measuring only the shark’s cerebrum. The complete shark brain is actually about 2 feet long from olfactory bulbs to brainstem.

The cerebrum is primarily responsible for learning and memory; the central area, for example, is thought to be connected to home ranging and social behavior in sharks.

But there’s much more to a shark’s brain. The cerebrum is attached to two huge olfactory organs. These structures detect and analyze chemical stimuli, contributing to the shark’s legendary sense of smell. Together with the hypothalamus and pituitary gland, they make up the forebrain. The hypothalamus produces hormones that regulate body processes such as heartbeat and metabolism, and the pituitary gland secretes hormones that control activities such as blood pressure and growth.

Working backward, the optic lobes of the midbrain interpret visual information. Recent research shows that the areas of the shark’s brain associated with visual input are larger than previously thought, suggesting that vision is an important and highly developed sense for sharks.

Finally, we get to the hindbrain. Here, the cerebellum coordinates body movement and some types of motor learning – for example, the fine adjustments needed for complex behaviors like attacking seals. And the brainstem is responsible for conveying sensory input from the shark’s inner ear, lateral line and electrosensory systems to the rest of the brain.

We still don’t fully understand how brain size and shape correlate to intelligence, but sharks are known to have one of the highest brain-to-body weight ratios among fish, closer to that of some birds and mammals. Their Y-shaped brain weighs about 1.2 ounces or .008% of the shark’s total body weight. In contrast, the human brain weighs about 48 ounces, or about 1.9% of total body weight.

Sharkopedia : Are Sharks Smart? |

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