Birds become good at avoiding danger by eavesdropping on the alarm calls of other birds—and the learning occurs without even seeing their peers or predators. Christopher Intagliata reports. 

　　鸟类通过偷听别的鸟类的警报叫声而变得善于躲避危险，这种学习行为甚至可以发生在见不到它们的同类及捕食者的时候。克里斯托弗·因塔利亚塔报道。

　　撰文播音：克里斯托弗·因塔利亚塔（Christopher Intagliata）

　　翻译：邱燕宁

　　审校：张清越

　　People speak thousands of languages in the world today. And same goes for the bird world. 

　　当今，人类世界有成千上万种语言。鸟类世界也是如此。

　　"Each bird species has effectively its own language." Andy Radford, a professor of behavioral ecology at the University of Bristol. "And there might be similarities between some languages just as there are in the human world. And then there are other languages that sound extremely different, even though they're conveying exactly the same meaning."

　　“每种鸟类都有自己的语言。”安迪·雷德福，布里斯托尔大学行为生态学教授说。“一些语言之间可能有相似之处，就像人类世界一样。还有一些语言听起来非常不同，尽管它们表达的意思完全一样。”

　　In fact some birds are known to pick up on the "language" of other species…in particular, they've learned to detect danger by eavesdropping on the alarm calls of other birds.

　　事实上，有一些鸟类已经学会了其他物种的语言，尤其是，它们学会了通过偷听其它鸟类的警报叫声来探测危险。

　　Radford and his colleagues wanted to investigate how that learning occurs. So they first played an alarm call that fairy wrens, an Australian bird, shouldn't be familiar with - a computer-generated alarm call <> meant to mimic a bird's. The unfamiliar sound had no effect on the fairy wrens.

　　雷德福和他的同事们想研究这种学习是如何发生的。因此，他们首先播放了一段仙女鹩莺(fairy wrens，一种澳大利亚鸟类)不应该熟悉的警报声，这是一种计算机生成的警报声，旨在模仿鸟儿的叫声。这种不熟悉的声音对仙女鹩莺没有任何影响。

　　But then the researchers paired the synthetic call with a chorus of alarm calls the wrens would recognize. <> And after this training, the sound of the initially unfamiliar synthetic call alone < was enough to send the birds ducking HA! for cover. The results are in the journal Current Biology. [Dominique A. Potvin et al., Birds Learn Socially to Recognize Heterospecific Alarm Calls by Acoustic Association]

　　但随后，研究人员将合成的叫声与鹩莺能够识别的警报叫声进行了配对播放。这次训练后，最初不熟悉的合成声现在即使单独播放也足以让鸟躲避寻求掩护。研究结果发表在《当代生物学》杂志上。

　　Radford says the study shows birds can learn from their peers, without ever seeing them…or a predator either. "And so I think that's the coolest thing of all, is that you can learn with your eyes shut about something really important in the natural world." 

　　雷德福说，这项研究表明，鸟类可以向同伴甚至者捕食者学习，哪怕看不到它们。“我认为最酷的事情是，即使闭上眼睛，你依然可以学习自然界中真正重要的东西。”