環(huán)球英語(yǔ) — 479：Walking Dolphins
Voice 1
Hello and welcome to Spotlight. I'm Ruby Jones.
Voice 2
And I'm Marina Santee. This programme uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live.
Voice 1
Port River, South Australia. A beautiful dolphin swims through the cool waters. Suddenly, the sea creature turns itself on its back, and pushes its body up head first! The dolphin is now balancing on its tail! It holds this position and moves like this across the water for a few seconds. Its white-grey body shines in the sun. Then the dolphin dives back into the water.
Voice 2
This dolphin is 'tail walking'. Dolphin trainers love to teach their dolphins tricks like this. Crowds love to watch them. But this dolphin does not belong to anyone. It lives freely in the wild! So, who taught this dolphin to tail walk? And why do scientists find this so interesting?
Voice 1
The dolphin creating the interest is named 'Billie.' Billie lives off the South Australian coast, near Adelaide. It was here that scientists first saw Billie tail walking. The scientists were from the Whale and Dolphin Conservation Society, or WDCS. This group works to protect dolphins around the world. The WDCS scientists saw a number of dolphins in the area perform the trick. And they were amazed. Tail walking is very rare among wild dolphins! They wanted to know how Billie and the others learned the trick.
Voice 2
In the early 1980s Billie had a bad experience. He got trapped behind a barrier, in a lake next to the sea. Billie became sick and was unable to return to the sea. So local people put him in a large dolphin tank. The tank was for dolphins that performed for the public. Billie lived in the tank with these other dolphins for several weeks. During this time he saw the life of the other dolphins. He saw them receive food for performing tricks - such as tail walking.
Voice 1
After Billie returned to the sea, scientists saw him tail-walking. But even more amazing - some other dolphins in the area also began tail walking! Scientists believe that Billie must have learned the behaviour from watching in the tank. Then Billie may have ‘taught’ the tail walking trick to the other dolphins. If this is the case, it would mean that Billie has demonstrated 'cultural behaviour.' Doctor Mike Bossley from WDCS said,
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'It would seem that tail walking in the Adelaide waters is another example of cultural behaviour in large brained animals. By cultural behaviour we mean behaviour that passes from one individual to another and becomes common in that particular social group.'
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Cultural behaviour is learned behavior in groups. It is common among humans. But, it is much rarer among animals! In fact, until recent years many people did not believe cultural behaviour existed among animals. However, today scientific reports show that particular animals do perform cultural behaviour. One such animal is the chimpanzee. And now Billie is making scientists investigate cultural behavior among dolphins. Cathy Williamson also works for the WDCS. She says:
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‘This behaviour by the Adelaide dolphins demonstrates their intelligence. And it proves even more that these animals are not supposed to be kept captive. Captive dolphins are not able to express natural behaviour. They are not able to form normal social groups with other animals.’
Voice 1
Captive dolphins do not live in their natural environment. They are limited to a particular area of water - such as a tank or water pool. Often, trainers teach these dolphins to perform tricks. And people pay money to watch. But an increasing number of people are against keeping dolphins captive purely for human enjoyment. And even keeping dolphins for ‘educational purposes’ causes some debate. The World Society for the Protection of Animals said in a statement:
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‘Most people now think there is only one acceptable argument to keep sea animals captive. And this is, when there are educational or scientific reasons. Dolphin fun centres make it look like they are there for educational purposes. But the truth is, looking at captive animals gives a false picture of the animals’ life. It provides no educational value. And what is worse, it stops people seeing the bad side of keeping animals captive.’
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Sea life centres say that there is value in their work. They say it is important to show children different sea creatures. If they do not, these children may never see these wild creatures for themselves.
Voice 1
Children crowd around the deep blue water. There is an air of excitement. They wait for the dolphin keeper to come. He walks out. He is carrying a container of fresh fish. He holds a fish out. The captive dolphins know what they must do. They push their beautiful bodies up out of the water. And they stand up on their tails, tail-walking across the water. Then, they receive their prize - a few fish. The children shout and clap their hands with excitement. Many of them have never seen a real dolphin before!
Voice 2
A long way away, in the waters of South Australia, wild dolphins swim freely. Every now and then one of them pushes its body up. It tail-walks across the water. Then, it dives back into the deep waters. There is no one clapping. There is no one throwing a prize of fish! But a scientist stands at a distance. Quietly, he records the dolphins’ movements. He is working to understand the behaviour of these amazing sea creatures. And he believes that the wild is the only place he can really learn natural behaviour. For him, it is in the wild that dolphins live as they were born to be: free.
