The shark movie "Jaws" came out in 1975. Ever since then, people have thought great white sharks are the most fearsome predators in the ocean. Now scientists say that might not be true.
Great whites hunt for seals off the coast of Northern California. They like the spot near the small Farallon Islands. Scientists noticed something when killer whales, known as orcas, swam by. The sharks immediately took off. They swam long distances to get away and did not return until the following year.
Scot Anderson is a shark expert. He said that when the orcas show up, they do not see "a single shark."
Killer Whales Make The Great Whites Look Small
Great white sharks are amazing hunters. They can grow up to 20 feet long and can weigh more than 4,000 pounds. Killer whales are even bigger. They can be up to 30 feet long and weigh 10,000 pounds or more!
White sharks swim 35 miles an hour. Killer whales can swim just as fast, and they hunt in groups, like wolves. They have been known to eat sharks. Two years ago, five dead white sharks washed up in South Africa. Killer whales had eaten their livers.
It seems amazing “when you see a 17-foot shark swim by," said Sal Jorgensen. He is also a shark expert. Then "along comes a bigger predator, the orca," he added. The shark suddenly seems small.
From 2006 to 2013, he and other scientists tracked 165 great white sharks. They stuck tiny tracking tags on the sharks. They used a 10-foot pole. The tags send out a signal to the scientists. The sharks traveled between the Farallon Islands and Tomales Point, north of San Francisco. They also went 50 miles south to Año Nuevo Island.
Scientists Track Activity Near The Islands
Jorgensen and Anderson compared what the sharks did with other information gathered by scientists. Scientists kept records on killer whales at the Farallon Islands. Information was gathered for 27 years.
They looked at the months between September and December. That is when many sharks hunt seals at the Farallons. They found that it was rare for killer whales to swim there at that time. In fact, over 27 years, orcas were there only 18 days during those months.
On those rare days when the two fearsome predators did meet, the white sharks took off. The hunters became the hunted.
In November 2009, killer whales arrived at the Farallons where 17 tagged white sharks were present. The killer whales only spent two hours in the area. The sharks bolted anyway. Seven of them swam south to Año Nuevo Island. The others swam 35 miles north.
None of the sharks came back until the following year.
Sharks Seek Safer Waters
Similar examples happened in 2011 and 2013. Killer whales came to the Farallons and the sharks left quickly.
Scientists are not sure why the white sharks swim away from the orcas. They say the sharks might be afraid they will be eaten. Perhaps they are being bullied by the killer whales. Orcas eat the seals and sea lions that sharks eat.
Jorgensen said people do not usually think that a shark would be afraid. It turns out that fear affects these predators. When scared, sharks change their plan. They end up hunting in "less preferred, but safer areas."
The most fearsome predator in the ocean is not the one from "Jaws." It is an animal that once performed tricks at SeaWorld. It is the orca.
Jorgensen said that the great white shark has had success as an ocean predator. Its success is not because of its fierce teeth, though. It is good at "knowing when to run."
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How much more does a killer whale weigh than a great white shark?
2,000 pounds
4,000 pounds
10,000 pounds
6,000 pounds
What is the MAIN idea of the article?
Scientists learned that great white sharks change their ocean plans whenever killer whales are nearby.
Scientists have spent 27 years tracking great white sharks that live near the Farallon Islands.
People are always shocked to see how small great white sharks are compared to killer whales.
People usually think of great white sharks as being scary because of the shark movie "Jaws."
What behaviors help great white sharks survive?
They hunt in groups, swim away from danger, and can swim 35 miles per hour.
They hunt in groups, are amazing hunters, and they swim away from danger.
They hunt in groups, are amazing hunters, and they can swim 35 miles per hour.
They are amazing hunters, swim away from danger, and can swim 35 miles per hour.
Read the paragraph below.
"Jorgensen said that the great white shark has had success as an ocean predator. Its success is not because of its fierce teeth, though. It is good at 'knowing when to run.'"
How does this paragraph support the MAIN idea of the article?
It shows that Jorgensen thinks great white sharks are bullied by killer whales.
It explains how Jorgensen was able to discover that great white sharks fear killer whales.
It shows that Jorgensen does not think great white sharks are scared of killer whales.
It explains why Jorgensen thinks great white sharks are good predators.
Why do great white sharks leave an area when killer whales arrive?
fear
curiosity
hunger
crowding
Complete the sentence. Killer whales showing up near South Africa caused:
the new studies on great white sharks
the deaths of some great white sharks
the great white sharks not to have enough food
the great white sharks to show up, too
How did scientists learn about the great white sharks’ behavior around killer whales?
They looked at how much food the great white sharks were able to eat after killer whales arrived.
They put tiny tags on both great white sharks and killer whales to see when they were together.
They used tiny tags to track the movement of great white sharks and compared it with other data.
They studied great white sharks that lived near the Farallon Islands and the ones near South Africa.
Climate change could cause killer whales to swim to the Farallons more often. What would be the outcome of killer whales visiting the Farallon Islands more often?
Great white sharks will be less scared of killer whales.
Great white sharks will become stronger predator
Sharks will hunt in other places.
The population of seals will decrease.
What is the text structure of the section “Killer Whales Make The Great Whites Look Small”?
The author uses cause and effect to show why dead sharks were found washed up on a South African coast.
The author uses chronological order to show how scientists tracked sharks over a seven year period.
The author uses compare and contrast to show the differences between the physical features and characteristics of sharks and killer whales.
The author uses problem and solution to show that sharks are being tagged to help locate them as they swim back and forth between the islands.
How does the picture contribute to the article above?
The picture shows the reader how the Great Whites hunt for seals.
The picture shows the Farallon Islands where whales like to hunt.
How does the picture contribute to the article above? RI 4.7
The picture shows the different types of species living in the same area.