『新东方在线托福听力』为托福考生准备了ETS托福TPO/Official 28 Lec 2听力练习：According to the professor, some corvids are known to hide their food. What possible reasons does she provide for this behavior?原文题目答案解析，TPO/Official 28 Lec 2听力原文范文音频翻译。

托福TPO/Official 28 Lec 2听力原文According to the professor, some corvids are known to hide their food. What possible reasons does she provide for this behavior?-新东方托福官方网校手机版

旁白：听一段动物行为的演讲。

Narrator: Listen to part of a lecture in an animal behavior class.

教授：就如你们知道的那样，研究员们对于发现动物们到底有多聪明一直都有着很大的兴趣。

Professor: As you know, researchers have long been interested in discovering exactly how intelligent animals are.

今天我们要谈谈有些动物好像有的一种认知能力——有能力在镜子中认出自己。

Today we are going to talk about a particular cognitive ability some animals seem to have—the ability to recognize themselves in a mirror.

教授：是的。黑猩猩以及其他一些灵长类动物，如非洲黑猩猩、大猩猩、红毛猩猩，当然也包括人类。

Professor: Right. Chimpanzees and other primates, chimps, gorillas, orangutans, and of course, humans.

但是，这个也能在大象和宽吻海豚中发现，有一点令人惊讶。

But it's also been found in elephants and bottlenose dolphins, a bit of a surprise.

大部分的动物都没有这个能力。

这个被称作为镜像自我认知，或MSR。

And it's called mirror self-recognition, or MSR.

学生：那么，这个是怎么发挥作用的？我的意思是，研究人员是怎么知道大象和黑猩猩能够认知他们自己？

Student: Well, how does it work? I mean, how do researchers know if elephants or chimps recognize themselves?

教授：研究人员给他们做了一个镜面标记测试。

Professor: Researchers give them a mirror mark test.

在这个镜面标记测试中，研究人员将一个标记放在动物身上，这个地方如果不通过照镜子，就无法看见或者闻见，比如放在他们脑袋的一侧。

In the mirror mark test, researchers put a mark on the animal where the animal is unable to see it or smell it or feel it, like on the side of their head, without looking in the mirror.

通常，当动物们第一次在镜子里面看到它们自己，它们认为它们看到了另一个动物。

Now, typically, when animals first see themselves in the mirror, they think they are seeing another animal.

通常它们会在镜子后面寻找那个动物。

Often they will look for this animal behind the mirror.

They may even exhibit aggressive behavior.

但是有些动物，在这段时间的探索之后，表现出了它们知道他们正在看着它们自己的行为。

But some animals, after this period of exploration, exhibit behaviors that show they know they are looking at themselves.

比如，大象会用鼻管碰触它们头上的标记。

For instance, elephants will touch the mark on their heads with their trunks.

现在，有假设认为灵长类及其他一些哺乳动物在认知进化等级上，独自站在了最高点。

Now, it's been assumed that primates and some other mammals stood alone at the top of the hierarchy of cognitive evolution.

但是最近，鸟类也被发现拥有一些相同的认知能力！

But recently, birds have been found to possess some of the same cognitive abilities!

特别是，研究人员在鸦科的鸟类中发现了这些能力。

In particular, researchers have discovered these abilities in corvids, birds of the corvidae family.

鸦科包括渡鸦、松鸦、乌鸦、喜鹊。

Corvids include ravens, jays, crows and magpies among others.

那么我们说的到底是哪几种认知能力呢？

And what kinds of cognitive abilities are we talking about?

渡鸦和一些哺乳动物有能力去为未来做计划，比如在一些它们以后能够找到的地方存储食物。

Well, corvids and some mammals have the ability to plan for the future, to store food for instance, in places where they can find it later.

事实上有人认为，由偷窃别人的事物而闻名松鸦，可能会很精确地隐藏它们的食物，因为它们会将它们的偷窃倾向投射到其他松鸦身上。

It's been suggested in fact that jays, corvids known for stealing each other's food, may hide their food precisely because they are projecting their own tendency to steal onto other jays.

让我们讨论最近用喜鹊做的一个研究。

So let's talk about a study recently conducted with magpies.

应为鸦科有这些认知能力，他们想看看它们是否能够有镜面认知能力。

And because corvids have these other cognitive skills, researchers wanted to see if they were also capable of mirror self-recognition.

所以，他们给这些喜鹊做了镜面标记测试，在喜鹊黑色的喉部羽毛上放了一个黄色的贴纸。

So they gave them the mirror mark test, placing yellow sticker on the birds' black throat feathers.

一开始，所有的喜鹊和其他动物一样，开始了同一种社会行为——在镜子后面寻找，等等。

At first, the magpies all engage in the same social behaviors that other animals do—looking behind the mirror, etc.

但是最终，有一些鸟，当它们看着镜子的时候，一直抓这个标直到他们摆脱它。

But eventually, some of the birds, while looking in the mirror, kept scratching at the mark until they got rid of it.

当没有镜子的时候，它们并没有抓这个标记。

And they didn't scratch at it when there was no mirror around.

学生：哇！其他一些鸟有这样的本领吗？

Student: Wow! Do any other birds have this ability?

教授：并不像我们所了解的那样。

有一个研究用了鸽子，这个研究中研究人员试图减少MSR到条件作用的程度，也就说，他们认为，在镜子中认知自己的能力是可以学习的。

There was a study using pigeons, where researchers attempted to reduce MSR to a matter of conditioning, that is, they claimed that the ability to recognize oneself in a mirror could be learned.

因此，这些研究人员培训了一些鸽子去通过镜面标记测试。

So these researchers basically trained some pigeons to pass the mirror mark test.

第一件事，从来没有人复制过这个研究。

但是更重要的是，它没有抓住要领。

But more importantly, it misses the point.

问题并不在于有些行为是否可以学习。

The issue isn't whether some behavior can be learned.

这个关乎于一个物种是否已经自发地发展了这种能力。

It's whether a species has developed this ability spontaneously.

学生：所以对于鸦科和黑猩猩，这个实验告诉了我们什么？

Student: So what does the test tell us about corvids or chimpanzees?

首先，它很重要，因为它将有自我意识的动物和无自我意识的动物区分开来。

For one thing, it is important because it sets animals with a sense of self apart from those without a sense of self.

但是，更重要的是，许多研究人员认为MSR暗示了其他一些高级认知能力。

But more importantly, many researchers believe that MSR is indicative of other advanced cognitive abilities.

自我意识，即使是在它最早期的阶段，可能会激起它们对其他人的认知，有能力去认知他人的观点，从别人的观点去看待世界。

Self-awareness, even in its earliest stages, might entail an awareness of others, the ability to see their perspective, to look at the world from another's point of view.

这个很关键，因为这个预示高水平认知的发展。

This is crucial, because it implies a high level of cognitive development.

这可能是向移情作用发展的第一阶段。

It's perhaps the first stage toward the development of empathy.

学生：但是和灵长类动物相比，鸟类的大脑太小了。

Student: But birds' brains are so small compared to primates.

教授：是的。尽管对于鸟类来说，鸦科类通常都有着较大的脑袋。

Professor: True. Though corvids do have unusually large brains for birds.

但是，（脑袋）大小并不是全部的原因。

有人认为灵长类动物之所以那么聪明是因为它们大脑的某一部分是鸟类没有的。

It's thought that primates are so intelligent because of a certain part of their brains, which birds simply don't have.

但是，研究人员认为，在鸟类大脑中，有一个区域管理着相似的认知功能。

But there is an area in birds' brains that researchers believe governs similar cognitive functions.

所以，灵长类动物和鸟类的大脑顺着不同的路径进化着，但是最终都有着相似的能力。

So primates and birds' brains have evolved along different tracks, but ended up with similar abilities.

When giving magpies the mirror mark test, why did researchers place the mark on the magpies’ throats?

According to the professor, some corvids are known to hide their food. What possible reasons does she provide for this behavior?

What is the professor’s attitude toward the study on pigeons and mirror self-recognition?

What does the professor imply about animals that exhibit mirror self-recognition?

According to the professor, what conclusion can be drawn from what is now known about corvids' brains?

Narrator 
Listen to part of a lecture in an animal behavior class. 
Professor 
As you know, researchers have long been interested in discovering exactly how intelligent animals are. Today we are going to talk about a particular cognitive ability some animals seem to have—the ability to recognize themselves in a mirror. 
Student 
Oh. I’ve heard about that. Chimpanzees have it. 
Professor 
Right. Chimpanzees and other primates, chimps, gorillas, orangutans, and of course, humans. But it’s also been found in elephants and bottlenose dolphins, a bit of a surprise. It’s very rare. Most animals don’t have it. And it’s called mirror self-recognition, or MSR. 
Student 
Well, how does it work? I mean, how do researchers know if elephants or chimps recognize themselves? 
Professor 
Researchers give them a mirror mark test. In the mirror mark test, researchers put a mark on the animal where the animal is unable to see it or smell it or feel it, like on the side of their head, without looking in the mirror. Now, typically, when animals first see themselves in the mirror, they think they are seeing another animal. Often they will look for this animal behind the mirror. They may even exhibit aggressive behavior. But some animals, after this period of exploration, exhibit behaviors that show they know they are looking at themselves. 
For instance, elephants will touch the mark on their heads with their trunks. 
Now, it’s been assumed that primates and some other mammals stood alone at the top of the hierarchy of cognitive evolution. But recently, birds have been found to possess some of the same cognitive abilities! In particular, researchers have discovered these abilities in corvids, birds of the corvidae family. Corvids include ravens, jays, crows and magpies among others. And what kinds of cognitive abilities are we talking about? 
Well, corvids and some mammals have the ability to plan for the future, to store food for instance, in places where they can find it later. It’s been suggested in fact that jays, corvids known for stealing each other’s food, may hide their food precisely because they are projecting their own tendency to steal onto other jays. 
So let’s talk about a study recently conducted with magpies. As I said, magpies are corvids. And because corvids have these other cognitive skills, researchers wanted to see if they were also capable of mirror self-recognition. So they gave them the mirror mark test, placing yellow sticker on the birds’ black throat feathers. At first, the magpies all engage in the same social behaviors that other animals do—looking behind the mirror, etc. But eventually, some of the birds, while looking in the mirror, kept scratching at the mark until they got rid of it. And they didn’t scratch at it when there was no mirror around. So they passed the test. 
ove a mark from their throats
Well, corvids and some mammals have the ability to plan for the future, to store food for instance, in places where they can find it later. It’s been suggested in fact that jays, corvids known for stealing each other’s food, may hide their food precisely because they are projecting their own tendency to steal onto other jays. 
So let’s talk about a study recently conducted with magpies. As I said, magpies are corvids. And because corvids have these other cognitive skills, researchers wanted to see if they were also capable of mirror self-recognition. So they gave them the mirror mark test, placing yellow sticker on the birds’ black throat feathers. At first, the magpies all engage in the same social behaviors that other animals do—looking behind the mirror, etc. But eventually, some of the birds, while looking in the mirror, kept scratching at the mark until they got rid of it. And they didn’t scratch at it when there was no mirror around. So they passed the test. 
Student 
Wow! Do any other birds have this ability? 
Professor 
Well, not that we know of. There was a study using pigeons, where researchers attempted to reduce MSR to a matter of conditioning, that is, they claimed that the ability to recognize oneself in a mirror could be learned. So these researchers basically trained some pigeons to pass the mirror mark test. 
But two things are noteworthy here. One, no one’s ever replicated the study. But more importantly, it misses the point. The issue isn’t whether some behavior can be learned. It’s whether a species has developed this ability spontaneously. 
Student 
So what does the test tell us about corvids or chimpanzees? 
Professor 
Good question. For one thing, it is important because it sets animals with a sense of self apart from those without a sense of self. But more importantly, many researchers believe that MSR is indicative of other advanced cognitive abilities. 
Self-awareness, even in its earliest stages, might entail an awareness of others, the ability to see their perspective, to look at the world from another’s point of view. This is crucial, because it implies a high level of cognitive development. It’s perhaps the first stage toward the development of empathy. 
Student 
But birds’ brains are so small compared to primates. 
Professor 
True. Though corvids do have unusually large brains for birds. But size isn’t the whole story. It’s thought that primates are so intelligent because of a certain part of their brains, which birds simply don’t have. But there is an area in birds’ brains that researchers believe governs similar cognitive functions. So primates and birds’ brains have evolved along different tracks, but ended up with similar abilities.