1 . Scientists have long known that a crow （乌鸦）native to New Caledonia is able to use tools. The birds use them to remove food from deep holes. Now, American researchers have discovered a second species of crow with the same ability. They reported on their experiments with Alala crows, which are from the Hawaiian Islands.
In the experiment, the researchers placed pieces of food in holes inside the wood. The holes were too deep for the crows to reach with their beaks(鸟喙). But, by using small pieces of wood held in their beaks, Alala crows quickly got the food. They used small objects as tools, sometimes changing them by shortening too-long sticks. They also made tools from plant materials.
“The crows use their beaks as people use thumbs on their hands. Tool use is rare in the animal kingdom. ” said Chritian Rutz of University of St. Andrews. “Current evidence strongly suggests that tool use is part of the species’ natural behavioral pattern(行为模式). These birds had no special training in the study, yet most of them were skilled at handling stick tools. ”
Bird experts claim finding out that the crows use tools is important discovery. “It makes us rethink how to look at the whole tool-use idea now and encourages us to go out and look for things that we may have ignored before. ”
All the Alala crows left in the world live in Hawaii. There were less than 20 Alalas left in the late 1990s when scientists decided to bring them into a protected area. Now, it is reported that there are over 100 birds living there. Scientists plan to release a small number of the birds back into the wild later.
1. What are the findings of American researchers?| A．Alala crows can also use tools. |
| B．It’s difficult for birds to look for food. |
| C．New Caledonia is home to some crows. |
| D．The Hawaiian Islands are full of rare birds. |
| A．The holes were very big and wide. |
| B．Alala crows could only use short sticks. |
| C．Alala crows got the food by working together. |
| D．Alala crows would deal with tools if necessary. |
| A．Using tools comes naturally to Alala crows. |
| B．Using stick tools is not easy for Alala crows. |
| C．Alala crows’ beaks look like people’s hands. |
| D．Alala crows won’t use tools without being trained. |
| A．Move all of them out of Hawaii. | B．Increase the population of them. |
| C．Set some of them free in nature. | D．Build more protected areas for them. |
