When they’re not making sweet love in the zoo or dodging¹ poachers in the wild, giant pandas sit around and munch² on bamboo. Their metabolic³ ability to take it easy has long baffled scientists.

除了在动物园里交配以及在野外躲避偷猎者，大熊猫总是在无所事事地啃竹子，而它们那可以将竹子消化的代谢能力长久以来一直困扰着科学家们。

Thanks to a study coming out of Chinese Academy of Sciences in Beijing and published in Science, we finally have some answers. For starters, giant pandas expend⁴ about 38 percent of the same energy as compared to other creatures of the same body mass. To maintain such a low metabolism⁵, they do indeed move slowly. In the wild, pandas spend just half of their time in motion; when they forage⁶, they average just 50 feet per hour. According to the study’s authors, that’s “very low.”

中国科学院刊载在科学杂志上的一项研究成果使我们有了些头绪。首先，和相同体型的其他生物相比，大熊猫只需消耗其38%的热量，而为了维持尽可能低的新陈代谢，它们确实是行动缓慢。在野外，大熊猫只花一半的时间用于运动，当它们觅食的时候，它们的平均速度只有每小时50英尺，研究负责人表示这个速度“非常慢”。

How’d they get their data? As Discovery reported:

那他们是怎么得到这些数据的呢？探索频道曾有过报道：

The researchers followed five captive and three wild giant pandas (Ailuropoda melanoleuca) for about a year. By using GPS trackers and analyzing⁷ chemicals excreted in the pandas’ poop, they were able to measure the amount of energy the pandas spent each day. Surprisingly, the pandas expended⁸ only about 38 percent of the energy that an animal with the same body mass would require.

研究员们跟踪观察了五只圈养大熊猫和三只野生大熊猫约一年时间，通过定位追踪和分析熊猫粪便，他们得以估算出熊猫每天消耗的热量总和。令人诧异的是，大熊猫只需消耗与它同等体型的动物所需热量的38%。

“We thought the metabolism of the panda would be low because the bamboo diet contains low energy,” said senior author Fuwen Wei, a professor of zoology⁹ at the Chinese Academy of Sciences in Beijing. “But it is very surprising that it is this exceptionally low, equal to the three-toed sloth¹⁰, and much lower than the koala.”

“我们认为熊猫的新陈代谢很低，因为竹子中含有的热量很少，”研究负责人魏福文（音译）说道，他是中国科学院动物学的专家，“但是我们没想到竟然会这么低，和三趾树懒差不多，比考拉要低三分之二。”

In addition to highly evolved behavior, biology comes into play, too. Autopsies¹¹ revealed low-energy wetware inside those big puffy bodies. Specifically, panda livers, kidneys and even their brains are smaller than those of other bears. This saves energy. Finally, their metabolic-managing thyroid hormones¹² are also lower than those seen in other similarly sized mammals. According to the researchers, the levels were lower than even those in hibernating¹³ black bears.

除了熊猫自身高度进化的行为以外，生物学也起了很大作用，研究员对熊猫的尸体进行了研究，发现在它们庞大的身躯中湿件的耗能非常低，特别是它们的肝脏、肾、甚至它们的大脑都比其他熊要小，这样就能节省热量，因此它们体内负责新陈代谢的甲状腺激素也比其它同等体型的哺乳动物要来的低，研究员说，这甚至比冬眠中的黑熊还要低。

So, in summary, pandas -- cute? Yes. Delicious? Maybe. Lazy and stupid? Definitely.

那么问题来了，熊猫萌吗？当然。好吃吗？不好说。又傻又懒？这是肯定的。