乌鸦因为吃快餐，胆固醇含量越来越高

Crows: They're just like us. They love fast food, but fast food doesn't always love them back.

乌鸦:它们和我们一样喜欢快餐，但快餐并不总是同样爱着它们。

A new study shows that eating cheeseburgers increased urban crows' cholesterol. (Photo: Dodge Stock/Shutterstock)

Urbanized crows survive on a diet that's mostly human leftovers. Oftentimes, it's fast food. Think pizza crusts, bread crumbs and other processed foods that don't occur naturally in nature. To see what kind of effect that diet was having on the birds' health, a team of ornithologists at Hamilton College in Clinton, New York, led a study to test the effect of cheeseburgers on urban crows' cholesterol levels.

都市化的乌鸦主要靠人类的剩饭剩菜生存。通常是快餐。想想披萨皮、面包屑和其他在自然界中不会自然出现的加工食品。为了了解这种饮食对乌鸦的健康有什么样的影响，纽约克林顿市汉密尔顿学院的鸟类学家团队领导了一项研究，测试了芝士汉堡对城市乌鸦胆固醇水平的影响。

Previous studies had shown that wildlife in urban areas, such as house sparrows, had high cholesterol levels. The scientists began by testing 140 crow nestlings in Davis, California, in a region that spanned rural to urban. And indeed, they found the more urban the bird, the higher its cholesterol.

此前的研究表明，城市地区的野生动物，如家养麻雀，胆固醇水平较高。科学家们首先在加州戴维斯对140只雏鸟进行了测试。事实上，他们发现这种鸟越城市化，它的胆固醇就越高。

Their next study took place in rural Clinton, New York, but this time, they supplemented the birds' diets with a high-cholesterol food: cheeseburgers. At one point, they were calling in 100 McDonald's cheeseburgers at a time. "They thought we were joking," Andrea Townsend, the lead researcher, told National Geographic.

他们的下一项研究是在纽约的克林顿乡村进行的，但这一次，他们用高胆固醇食物补充了鸟儿的饮食:奶酪汉堡。有一段时间，他们一次叫来100个麦当劳芝士汉堡。“他们以为我们在开玩笑，”首席研究员安德里亚·汤森(Andrea Townsend)告诉《国家地理》(National Geographic)杂志。

Just like humans, crows should practice moderation when it comes to fast food. (Photo: PierreSelim [CC by SA 3.0]/Wikimedia Commons)

Notably, the cholesterol levels did not have an impact on the birds' survival. And the baby crows who received a burger-rich diet ended up, technically, in "better body condition" than their rural counterparts. Although "if you’re a chubby crow, essentially, that’s considered to be good condition,” Townsend noted.

值得注意的是，胆固醇水平对鸟类的生存没有影响。从技术上讲，吃了富含汉堡的食物的乌鸦宝宝的“身体状况”要比它们的农村同伴好。尽管“如果你是一只胖嘟嘟的乌鸦，基本上，这被认为是一种良好的状态，”汤森指出。

The study, published in the scientific journal The Condor, believes that crows might develop heart disease later in life, but more research is needed.

这项发表在科学杂志《秃鹰》上的研究认为，乌鸦可能会在晚年患上心脏病，但还需要更多的研究。

For now, just like us, the birds would do better eating cheeseburgers in moderation. If you want to continue feeding the birds in your neighborhood, the scientists suggest something less processed, and as close to natural as you can get.

现在，就像我们一样，鸟类在适度食用芝士汉堡方面会做得更好。如果你想继续喂养你附近的鸟类，科学家们建议一些不那么加工的，尽可能接近自然的食物。