科学美国人60秒 大脑小的鸟儿更容易被杀（在线收听）

The old expression “bird brain,” referring to a small or inadequate brain size—it’s not all that accurate. Take crows, for example, and other corvids,like jays and magpies. “Many corvids have relatively large brains for their body size, and can do amazing things.” Anders M?ller, an evolutionary biologist at the French National Science Research Council. “So this ‘bird brain’ expression is a little bit simplified.” Some birds are so intelligent that they’re informally referred to as “primates with feathers.”

旧的表达“鸟的大脑”指的是大脑尺寸较小——但是这样的描述并不正确。就以乌鸦以及其他鸦科如松鸡和喜鹊为例。“许多鸦科大脑与其身体尺寸相比较，尺寸比较大，并且这些鸦科动物可以做令人吃惊的事情。”Anders M?ller是法国国家科学研究委员会的进化生物学家。“所以，“鸟的大脑”这样的表述有一点简单化了。”有一些鸟类非常的聪明，以至于它们被人类通俗地称为“长着羽毛的灵长类动物”。

But even among the smartest bird species, there’s still natural variation in brain size. Which is a big deal—when it comes to being hunted. M?ller worked with a taxidermy shop in Denmark, which had data on nearly 4000 birds brought in to be stuffed since 1960. A lot of the birds were just found dead—hit a window or wire—and people picked them up. But 300 of the specimens had been hunted.

但是，即使在最聪明的鸟类中，它们的大脑尺寸也存在自然变异。这是一件大事——当鸟类在被捕猎的时候。M?ller和丹麦的一家标本店合作，这个标本店里有自从1960年将近4000只鸟类的标本数据。很多人们发现了死了的鸟——由于撞击窗户或电线——人们将这些鸟儿捡起。但是其中300个鸟类的标本是通过猎杀制作的。

So M?ller’s team then compared the brain sizes of birds that got shot to those that didn’t. They controlled for the birds’ age, sex, body size, and species. And they found that the hunted specimens’ brains were actually five percent smaller, on average, than the brains of birds that died by other means. “The surprising thing is that, if you make a similar kind of analysis of liver or heart size, there is absolutely no difference there. So this is specific to the brain.” The results are in the journal Biology Letters.

所以，M?ller的团队将那些被猎杀的鸟类的大脑尺寸和其他鸟类的大脑进行比较。他们控制了鸟类的鸟类、性别、身体尺寸以及物种。研究人员发现被猎杀的鸟类的大脑尺寸，比因其他原因死亡的鸟类的大脑相比，小百分之五。“令人惊讶的是，如果对肝脏或者心脏的尺寸进行类似分析，尺寸没有任何的区别。所以，尺寸的区别是大脑的独有特征。该研究结果发表在《生物学报》杂志上。

The researchers assume that individuals with larger brains had what they called “superior escape ability.” That is, they were better at not getting shot.

研究人员认为拥有较大尺寸大脑的个体具有“出众的逃生能力”。也就是说，他们不易遭到射击。

As game season begins, M?ller has this observation for hunters: “When you are sitting at the dinner table and eating the duck that you managed to shoot, with all likelihood it’s one with a disproportionately small brain.” Most certainly food for thought.

随着赛季开始，M?ller对捕猎者说道：“当你坐在餐桌旁，吃着你射杀的野鸭时，很有可能这只野鸭具有一个非常小的大脑。”这的确是引人深思的事情。