Dolphins learn special foraging(捕食) techniques from their mothers and it's now clear that they can learn from their buddies as well.
"Dolphins are indeed very clever animals. So it makes sense that they are able to learn from others," says Sonja Wild, a researcher at the University of Konstanz in Germany.
The bottle-nose dolphins that live in Shark Bay, Western Australia, have been studied for decades, and scientists have identified over a thousand individuals by looking at the unique shape and markings of their dorsal fins. Researchers know what families the dolphins belong to, and keep track of their close associates.
Wild and her colleagues have closely examined how dolphins learn particular strategy for catching fish---one that involves using the empty shells of large sea snails. A dolphin will chase a fish to one of these shells, and then they insert their beak into the shell, bring the whole thing up to the face. After that, they shake it up above the water surface to drain the water out of the shell until the fish basically falls into their open mouth.
Whether or not dolphins caught fish in this way didn't seem to be explained by how many shells were lying around their hunting area, nor whether a dolphin was genetically related to another dolphin that knew how to do it.
The new observations of wild dolphins learning from their peers is "exciting, "says Diana Reiss, a dolphin cognition researcher at Hunter College, CUNY, "It tells us about the source of some these behaviors. It seems like they're not relying on just learning from mom when they're out there. They seem to be observing others, watching what they're doing and acquiring it from others in their social group."
Being able to learn from peers may help animal populations survive in a changing environment.
| A．The best explanation is that dolphins learned this method from a close associate. |
| B．Research shows that this behavior gets passed down almost exclusively through the maternal line. |
| C．Young dolphins spend years in close association with their mothers and naturally tend to adopt their mothers' ways |
| D．Because while knowledge from previous generations has been tested by time, certain behaviors may become less useful if conditions change. |
| E．Take, for example, the clever trick that some dolphins use to catch fish by trapping them in seashells. |
| F．Based on this assertion, we can't discount the possibility that they innovate individually on their own. |
相似题推荐
【推荐1】Have you ever wondered why elephants get so big? Thanks to their enormous size, they have been able to survive for thousands of years in all kinds of circumstances. Their size has allowed them to reach high food sources, knock down trees instantly and find water underground. Not only does their size benefit them but also their ecosystem.
Elephants use their size to create holes in the ground to find water. During droughts, they will start to dig holes to find water that might be stored underground. Elephants are not just helping themselves but also smaller species. Those water holes that they create become water sources for other species. These holes are essential, especially during droughts. Without elephants, some smaller species would not have access to water.
Elephants spend a lot of time eating. To be exact, they spend 12 to 18 hours a day eating. Since they eat so much, they are always on the shift to find food sources. These magnificent creatures can walk up to 50 miles a day. As elephants make their way to their next location, they drop dung filled with seeds along the way. Once on the ground, those seeds will begin to grow. The elephant dung helps the seeds shoot. This helps increase the biodiversity of plants and trees.
Elephants create homes for other species. Another one of the roles and importance of elephants in the ecosystem is creating homes for smaller creatures. Unexceptional small species do not have the size to knock down trees or create holes in the ground to create a home. These animals rely on elephants to do that for them. Elephants use their powerful kicks and teeth to knock down trees. Small species will then use that as shelter. Furthermore, elephants help spread seeds that grow into trees and plants that animals will call home.
1. What is the cause of elephants’ survival for thousands of years?| A．Their huge size. | B．Rich food sources. |
| C．Their unique shape. | D．Plenty of water underground. |
| A．They eat a lot. | B．They knock down trees. |
| C．They cover a long distance. | D．They produce waste along the way. |
| A．They make shelters for other species. |
| B．They dig water holes for other creatures. |
| C．They help the seeds of plants spread and grow. |
| D．They find food sources for other plants and animals. |
| A．It encourages people to protect elephants. |
| B．It talks about the importance of elephant dung. |
| C．It introduces the benefits of elephants to the environment. |
| D．It informs readers of the reasons why elephants grow big. |
【推荐2】Brownie and Spotty were neighbor dogs who met every day to play together. Like pairs of dogs you can find in most any neighborhood, these two loved each other and played together so often that they had worn a path through the grass of the field between their respective houses.
One evening, Brownie's family noticed that Brownie hadn't returned home. They went looking for him with no success. Brownie didn't show up the next day, and despite their efforts to find him, by the next week he was still missing. Curiously, Spotty showed up at Brownie's house alone. Barking, whining and generally pestering Brownie's human family. Busy with their own lives, they just ignored the nervous neighbor dog.
Finally, one morning Spotty refused to take "no" for an answer. Ted, Brownie's owner, was steadily harassed by the furious, adamant little dog. Spotty followed Ted about; barking insistently, then darting toward nearby empty lot and back, as if to say, "Follow me! It's urgent!"
Finally, Ted followed the frantic Spotty across the empty lot as Spotty paused to race back and bark encouragingly. The little dog led the man under a tree, past clumps of trees, to a desolate spot a half mile from the house. There Ted found his beloved Brownie alive, one of his hind legs crushed in a steel leg hold trap. Horrified, Ted now wished he'd taken Spotty's earlier appeals seriously. Then Ted noticed something quite remarkable.
Spotty had done more than simply led Brownie's human owner to his trapped friend. In a circle around the injured dog, Ted found an array of dog food and table scraps which were later identified as the remains of every meal Spotty had been fed that week!
Spotty had been visiting Brownie regularly, in a single minded quest to keep his friend alive by sacrificing his own comfort. Spotty had evidently stayed with Brownie to protect him from predators, snuggling with him at night to keep him warm and nuzzling him to keep his spirits up.
Browni’s leg was treated by a veterinarian and he recovered. For many years thereafter, the two families watched the faithful friends playing and chasing each other down that well-worn path between their houses.
1. What's the correct order of the following?① They couldn’t find him everywhere.
② Spotty went to Brownie’s master's house to ask for help.
③ One evening, Brownie was missing.
④ Spotty found Brownie and helped him by giving him food.
⑤ They play together happily again.
| A．③①②④⑤ | B．⑤③①④② | C．③①④②⑤ | D．③①④⑤② |
| A．Spotty took Brownie's food to him every day. | B．There was a natural path between the two houses. |
| C．The legs of Brownie were hurt by the steel trap. | D．Brownie disappeared for more than a week. |
| A．Ted noticed Spotty’s earlier actions. | B．Brownie’s family were thankful to Spotty. |
| C．They asked the police to find Brownie for them. | D．Spotty led Brownie’s owner to feed him. |
【推荐3】Banff National Park is home to an amazing wildlife population. But the busy Trans Canada Highway that cuts through the park is a hazard to the lovely animals. To address the problem, Banff first put up wildlife fencing on either side of the highway to discourage animals from entering the busy road. Then, since 1996, they’ve opened six wildlife overpasses and 38 underpasses to help the animals cross the highway in safety.
I was fortunate to visit Banff’s Red Earth Overpass with Trevor Kinley, the project manager with Parks Canada. He told me that so far, they have documented 10, 000 safe animal crossings on this overpass alone. “Some animals have learned how to use the crossings much more quickly than others. Black bears are the fastest learners, followed by deer. Wolves and lions take the longest to work out how to use them,” Kinley said, laughing. “But those animals that are slower to adapt are usually more capable and determined at figuring out the safest way to cross those overpasses and underpasses.”
There is some criticism (批评) that channeling so much wildlife into a few bridges and tunnels is like making a trap for the animals, offering big animals an easy meal on either side. “But research has shown that this is not the case,” Kinley assured me. “There are no more killings around the crossings than there are anywhere else in the park.”
Walking over the Trans Canada and then walking underneath through one of the tunnels, I was amazed to see the fresh tracks of black bears, wolves, deer and many kinds of smaller animals. Somehow, all these animal footprints made me so delighted, knowing that all this wildlife was passing safely under and over the longest road in Canada.
Hopefully, the success of the wildlife crossings in Banff will continue to inspire similar solutions around the world, where human pressure on wildlife continues to grow.
1. Which of the following best explains “hazard” underlined in paragraph 1?| A．Shelter. | B．Habitat. | C．Access. | D．Danger. |
| A．They are stupid animals. | B．They are cautious learners. |
| C．They are very dangerous. | D．They are good at adapting. |
| A．There are too many bridges and tunnels. | B．More killings might happen at the crossings. |
| C．Many animals will be trapped in the crossings. | D．Illegal hunting might happen in the park. |
| A．Concerned. | B．Indifferent. | C．Supportive. | D．Skeptical. |
