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This is Scientific American 60-second Science, I'm Christopher Intagliata.

这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔格里塔。

High cholesterol¹ affects a third of American adults. But it's not just us! Studies have indicated that cholesterol is also o?n the rise in other animals.

高胆固醇问题影响着美国三分之一的成年人。但影响的不只是我们人类！研究表明，其它动物体内的胆固醇水平也在上升。

"And in all of these studies the idea was, well, they hypothesised that it was probably due to interactions with people and eating our food, but they didn't actually show that."

“所有这些研究的猜想是，原因可能是动物与人类的互动以及食用我们的食物，但研究并未证明这一点。”

Andrea Townsend is an avian ecologist at Hamilton College in upstate New York. And she found that urban crows did have higher cholesterol than rural crows.

纽约北部汉密尔顿学院的鸟类生态学家安德莉亚·汤森德说到。她发现，城市乌鸦的胆固醇水平确实比乡村乌鸦高。

But then she took the next logical step in her research. She went to McDonald's. "We'd pick up 125 burgers at a time. Once one of them wanted to know what we needed all these burgers for, and I started to explain, but they just kind of waved me away halfway² through. So..."

但随后她在研究中迈出了合乎逻辑的下一步。她去了麦当劳。“我们会一次买125个汉堡。曾经有人想知道我们买这么多汉堡做什么，我开始解释，但他们听了一半就挥手让我离开。所以……”

Of course, she needed all those cheeseburgers to feed crows and to monitor their diet—to determine if eating our fast food really does raise the birds' cholesterol.

当然，她要用所有这些芝士汉堡来喂乌鸦，并监控它们的饮食——以确定乌鸦食用我们的快餐是否真的会提高其胆固醇含量。

"So the way you 'supplement your nestlings' is: we'd go to their nest trees, we'd toss the cheeseburgers, three to five a day, under their nest trees. And the parents would immediately swoop³ down, pick up the burgers and bring them to their nestlings."

“所以，‘为雏鸟补充营养’的方法是：我们会每天在鸟巢所在的树下扔三到五个芝士汉堡。雏鸟的父母会立即俯冲下来，叼起汉堡，将汉堡带给雏鸟。”

And as you might expect, crows that dined on cheeseburgers did indeed have higher cholesterol than crows who did without. But here's the surprising thing: higher cholesterol didn't affect crows' chances of survival over a three-year period. And in one population, birds with higher cholesterol were arguably in better condition than other crows. Meaning chubbier⁴.

正如你所料，吃芝士汉堡的乌鸦的胆固醇确实比没吃汉堡的要高。但令人惊讶的是：在三年的时间里，高胆固醇并没有影响乌鸦的生存率。在一个种群中，可以说，胆固醇高的乌鸦比其它乌鸦的状况更好。也就是说，更胖。

The results are in the journal the Condor⁵.

研究结果发表在《秃鹰》期刊上。

Crows can live more than 15 years, and Townsend says maybe a high-cholesterol diet makes its mark later in life, as it does in humans. And if you're still wondering, "Why study this?"

乌鸦能存活超过15年，汤森德说，高胆固醇饮食可能会在以后的生活中留下印记，就像其在人类身上的影响一样。如果你还想知道“为什么要研究这个？”

"I would say this is an important question, because there are lots of other species that also live in urban areas and eat our food. And some of them are endangered. So it is an important question: How will our food affect the health of wild animals?"

“我会说，这是个重要的问题，因为许多其它物种也生活在城市地区，并食用我们的食物。其中一些是濒危物种。因此这是一个重要的问题：我们的食物会如何影响野生动物的健康？”

And as we urbanize more of the globe, our dietary influence might have even wider effects.

随着全球城市化程度的提高，我们的饮食影响可能会产生更广泛的效应。

As for Townsend, crows are known to be highly skilled at recognizing humans, and she says the study made her a celebrity⁶.

至于汤森德，众所周知乌鸦非常善于识别人类，她说这项研究让她成为了名人。

"During this study, especially when I was walking around, the crows would follow me around campus. They often just follow me around campus anyway; they follow my car. I was getting some notoriety on a broader scale with crows. So I would be going to... like getting gas, and the crows in the gas station would be cawing a special caw just for me. It seemed like a recognition caw. So it's like 'caw caw caw.'"

“在这项研究期间，特别是在我散步时，乌鸦会在校园里一直跟着我。它们经常在校园里跟着我，追我的车。我因为乌鸦而‘臭名远扬’。比如我去加油，加油站的乌鸦会只对我发出特殊叫声。就好像是认出我一样。就是‘哇哇’的叫声。”

After all, a free lunch sure does seem like something to squawk about.

毕竟，免费午餐确实是可以大声叫的事情。

Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.

谢谢大家收听科学美国人——60秒科学。我是克里斯托弗·因塔利亚塔。