英語聽力：自然百科 Giant Pandas 大熊貓的困境

There is just something about them. Maybe it’s the way they plow through bamboo with no regard to dinner table etiquette, or maybe it’s the leisurely strolls. From the outset, a panda’s life appears to be pretty easy. But appearances don’t tell the whole story.

Their natal habitat in China continues to disappear. With about 1,000 left living in the wild, giant pandas are one of the most critically endangered species in the world. As a result, conservationists are doing their best to get captive pandas to reproduce, a difficult task given the animal's biology.

But when you have a female that only cycles once a year, you know, if you don’t get her to breed that year, you have to wait again, so that’s a big challenge with pandas.

Rebecca Snyder is the curator of giant panda research at Zoo Atlanta where Yang Yang and his female counterpart Lun Lun are big attractions, both were closely studied from the moment they were born. Yang Yang, the male, was kept with his mother for almost a full year, a departure of captive breeding programs which usually separate cubs from their mothers at a much earlier age.

We think that removing these cubs at a very young age maybe prevents them from developing properly, socially that they are not having a chance to socialize with their mothers or learn from their mothers and that might be one of the reasons that some of them are not successful in breeding later in life.

Snyder and her colleagues recently tested that theory. The female Lun Lun, went into estrus, sexually mature, she was now ready to mate. But Yang Yang just was't getting the message.

She did everything she could do basically like suddenly slapped and everything you could expect. And he again was very interested in her, and you know, did everything he could do, too, but I think it's just gonna take him a little while longer to catch up with her.

These pandas who were raised together are being forced to go their separate ways whenever romance is not in the air. The giant panda is by nature solitary. So to simulate life in the wild, scientists at Zoo Atlanta separate Yang Yang and Lun Lun once a month for 24 hours. Researchers are finding that the male and female have distinctly different responses to their solitaryconfinement.

She used to show a little bit more overreaction when they were separated, at least go and look at him if she could, or sometimes scratch or paw a little bit at the barrier. But the last few times, she has not seemed to be particularly upset by being apart from him. He on the other hand, has been upset each time, really seems to prefer to be with her.

So while Lun Lun is acting like a spurned lover, after repeated separations, Yang Yang may be starting to understand what he is missing. In an echo of human behavior, when she plays hard to get, he suddenly can’t get enough of her.

It gets a good sign for the future. That’s the way males should be, generally for them to be good breeders, usually they should be interested in the female, wanting to interact with the female.