This is Scientific American — 60-Second Science. I'm Karen Hopkin.
Bats are sophisticated communicators. And not just when they're in vampire form. "I'm Dracula." New research finds that Egyptian fruit bats actually have regional dialects, depending on the bat chatter that surrounds them as they grow up. The study is in the journal PLOS Biology.
Among humans, one person's howdy is another one's g'day. Wild populations of bats also display group-specific vocalizations. But how do these vocal characteristics arise? Do they reflect innate, genetic differences or are they learned? And if bat accents are acquired, who are these furry fliers imitating? Their parents? Or their roost-mates?
To find out, Yossi Yovall at Tel Aviv University and his colleagues captured 15 pregnant fruit bats and divided them into three groups, each of which was housed in its own separate box. The mothers gave birth inside these boxes and their babies, called pups, lived there for a full year. During that time, the researchers exposed the pups to a select symphony of bat sounds. Fruit bats in the wild are reared in colonies that contain dozens to thousands of individuals, so they're used to being surrounded by a cacophony of calls and other vocal communiques.
For one of the boxes, Yovall and his team exposed the young batlings to a selection of squeaks that were biased toward the higher frequencies. Pups in the second box heard lower-pitched peeps. And the third box got a random sampling of fruit bat hits that was heavy on the mid-range frequencies but also included those at either end of the aural spectrum.
"And what we found is that they were influenced by the playback that they heard."
"So the control group was using a vocal repertoire that was identical to their mothers and identical to fruit bats in the colony here in Israel. But the two manipulated groups were using different dialects...we actually were able to create three different groups of fruit bats with three different dialects in the lab."
Of course, birds are famous for their songs. Which the males learn from tutors, typically their dads. But Yovall says when it comes to vocal learning, bats march to a different drummer.
"Here we show that even though the pups were with their mothers, they were exposed to their mother's normal repertoire, they were still influenced by the background vocalizations that they heard. Now this is probably extremely reasonable in the case of bats because bats roost in these caves with many hundreds of individuals...we believe that this process, which we call crowd vocal learning, because you learn from the entire crowd, is relevant for many other animals that live in crowded colonies."
As the researchers note in their paper, this sort of social learning is sometimes called "culture". Even if you're living in a cave.
Thanks for listening for Scientific American — 60-Second Science. I'm Karen Hopkin.
蝙蝠之间的交流很复杂 。不只是在它们吸血的时候 。“我是吸血鬼德古拉 。”一项新研究发现，埃及果蝠实际上有自己的地域方言，而方言取决于它们成长过程中周围的交流声 。这项研究结果发表在《公共科学图书馆·生物学》期刊上 。
在人类中，人和人的语言是不同的 。野生蝙蝠群也有类群特异性的发声 。但是，这些声音特性是如何产生的呢？是先天遗传差异性的反映，还是后天习得的？如果蝙蝠口音是后天习得的，那这些毛茸茸又会飞的动物是在模仿谁呢？是它们的父母？还是共享栖息处的同伴？
为了找到答案，特拉维夫大学的尤西·约瓦尔和同事捕获了15只怀孕的果蝠，并将它们分成三组，每组被放入单独的盒子里 。雌性果蝠在这些盒子里产下幼崽，然后和幼崽一起在盒子里生活一整年 。在这一年里，研究人员让这些幼崽接触它们所选择的蝙蝠声音交响曲 。野生果蝠在包含几十至几千只同类的群体中长大，所以它们习惯置身于刺耳嘈杂的叫声和其他声音之中 。
对于其中的一个盒子，约瓦尔和团队将小果蝠暴露在一些较高频率的吱吱声中 。而第二个盒子的小果蝠听到的是低音吱吱声 。第三个盒子是随机取样的果蝠，它们接触的声音以中频范围为主，不过也包括听觉范围两端的声音 。
“对照组使用了和它们母亲完全一样的声音，同时也和以色列区域的果蝠声音相同 。但是两个被操纵小组使用了不同的方言，实际上我们能够在实验室里用三种不同的组合方法创造出三组不同的方言 。”
当然，鸟类以歌声闻名 。这歌声是雄鸟从导师——通常是父亲——那里学来的 。但是约瓦尔表示，在鸣叫学习方面，蝙蝠可以学到不同的声音 。
“我们的研究显示，即使小蝙蝠和母亲在一起，而且听到的是母亲的正常声音，它们仍会被它们听到的背景声音所影响 。就果蝠来说，这种情况可能极为合理，因为它们同数百只同类栖息在这些洞穴里，我们将这一过程称为“群体发声学习”，我们认为，因为你从整个群体中学习，所以与生活在拥挤群体中的许多其他动物有关 。”
正如研究人员在论文中指出的那样，这种社会学习有时被称为“文化” 。即使你生活在山洞里 。
谢谢大家收听科学美国人——60秒科学 。我是凯伦·霍普金 。
1. divide into （使）分开；（使）分散；（使）分裂；
例句：It will be easiest if we divide them into groups.
2. be used to doing sth. 习惯于；
例句：Most people have no objection of these various restrictions, who in order to live have been used to sitting down under it.
3. be identical to 完全相同的；同样的；
例句：Your voice is identical to hers.
4. be exposed to 使受…的影响(或熏陶)；使接触；
例句：We are all exposed to such advertisements every day and their effect on us cannot be denied.