题目内容：

Birds Can “Read” Human Gaze

We all know that people sometimes change their behavior when someone is looking their way. Now, a new study reported online on April 2nd in Current Biology shows that jackdaws (寒鸦) — birds related to crows with eyes that appear similar to human eyes — can do the same.

“Jackdaws seem to recognize the eye’s role in visual perception (视觉), or at the very least they are extremely sensitive to the way that human eyes are directed,” said Auguste von Bayern, formerly of the University of Cambridge and now at the University of Oxford.

When presented with a preferred food, hand-raised jackdaws took longer to get the reward when a person was directing his eyes towards the food than when he was looking away, according to the research team led by Nathan Emery of the University of Cambridge and Queen Mary University of London. The birds hesitated only when the person was not known to them and thus potentially threatening.

In addition, the birds were able to understand human communicative gestures, such as stare change and pointing, to help them find hidden food, they found. The birds were unsuccessful in using unmoving signals, including eye stare or head direction.

Unlike most birds, jackdaws’ eyes have a dark pupil (瞳孔) surrounded by a silvery white iris (虹膜). The researchers said they believe jackdaws are probably sensitive to human eyes because, as in humans, eyes are an important means of communication for them. The hand-raised birds examined in the study may be even better than wild jackdaws at attending to human stare and responding to the gestures of the people who have raised them.

The findings are particularly notable given that most other species examined so far, including our closest relatives, the chimpanzee and “man’s best friend,” the dog, are not particularly sensitive to eye direction and eye stare, von Bayern said. Rather, she continued, chimps and dogs seem to rely on other signals such as head or body direction in determining the looking direction of others. The results suggest that birds may deserve more respect for their mental abilities.

“We may have understated the psychological world of birds,” von Bayern said. “Jackdaws, among many other birds, form pair ties for life and need to have much in common and work together with their partner, which requires an efficient way of communicating and sensitivity to their partner’s viewpoint.”

1.A hand-raised jackdaw hesitates to take a preferred food when the feeder ______.

A. is unfamiliar to the bird    B. is looking away from the food

C. holds the food in his hand    D. is looking at the food

2.According to the researchers, jackdaws can notice human eye direction probably because ______.

A. their eyes also have a dark pupil

B. they are far more intelligent than other birds

C. they are mostly hand-raised by humans

D. like humans, they also use eyes to communicate

3.Why does the author refer to chimpanzees and dogs?

A. To suggest that they are much better at understanding stare change.

B. To make clear that they rely on other means in determining people’s intention.

C. To show that they communicate more frequently with humans than jackdaws.

D. To reflect how unique jackdaws are in being able to notice stare direction.

4.What does the research finding suggest?

A. We know embarrassingly less about birds than we assume.

B. Not all jackdaws are good at attending to human stare.

C. We may have understated jackdaws’ mental abilities.

D. The closer we communicate with animals, the better we understand them.