?Bats are sophisticated communicators. And not just when they’re in vampire form. 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.蝙蝠都是“交流大師”,這里所說的蝙蝠并不僅僅指吸血蝙蝠。一項新的研究發(fā)現,事實上,埃及果蝠間存在著方言,這種方言的形成取決于蝙蝠寶寶成長時周圍蝙蝠所發(fā)出的聲音。這項研究發(fā)表在《公共科學圖書館·生物學》雜志中。
? 撰文/播音:凱倫·霍普金 翻譯:曲薈龍 審校:許楠
? 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? 人類社會中,有人會問候“你好啊”,有人會問候“吃了嗎您”。野生蝙蝠種群中也存在有這種現象,即某個群體會呈現出特有的聲音分化。但是這種現象是如何產生的呢?它反映的是先天的、遺傳的差異?還是后天習得的差異?如果蝙蝠的叫聲是通過后天學習而獲得的,那么這些毛茸茸的小家伙們會模仿誰呢?它們的父母嗎?還是與它們一起棲息的同伴們呢? 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. 為了尋找答案,以色列特拉維夫大學(Tel Aviv University)的約西·尤沃(Yossi Yovall)和他的同事們捕獲了15只懷孕的果蝠,并將它們分成三組,每組分別放置在彼此分開的盒子中。母蝙蝠們在這些盒子中產下幼崽,并在這里生活整整一年。這段時間里,研究人員將蝙蝠幼崽們放置在特定的蝙蝠聲音中。野生果蝠群包含有幾十個甚至幾千只不同的蝙蝠,因此果蝠幼崽已經習慣了周圍存在著嘈雜的叫聲或是其他的聲音。 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. 尤沃及團隊將第一個盒子里的蝙蝠幼崽放置在相對高頻的蝙蝠聲中,第二個盒子里的蝙蝠幼崽放置于相對低頻的聲音中。第三個盒子使用隨機抽取的果蝠聲音樣本,這些樣本以中等頻率為主,但也包括了在聽覺譜兩端的聲音。 “And what we found is that they were influenced by the playback that they heard.”Yossi Yovall. “我們發(fā)現,果蝠幼崽會受它們所聽的‘背景音’的影響。”約西·尤沃表示。 “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.” “對照組使用與幼崽母親完全相同的聲音,這種聲音和以色列當地的果蝠種群聲音一致。但是在兩個實驗組中,我們使用的是與之不同的、果蝠間的‘方言’。實際上,我們在實驗室里創(chuàng)造了三種不同的果蝠——它們擁有三種不同的方言。” 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. 我們都知道鳴叫是鳥類的‘特色’。雄鳥從它們的‘導師’那里學習鳴叫,而它們的導師通常是他們的父親。但是尤沃認為,在鳴叫學習這一方面,蝙蝠和鳥類有所不同。 “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.” “我們的研究顯示,盡管蝙蝠幼崽和它們的母親生活在一起,會受到母親叫聲的影響,但同時也會受到背景聲音的影響。在蝙蝠群中,這是一種極其合理的推斷。因為蝙蝠和成百上千只同類共同棲息在洞穴中…我們將此稱之為‘種群鳴叫學習’過程,因為幼崽會向整個種群學習,我們認為這個過程在許多其他生活在高密度群居種群中的生物中也存在。” As the researchers note in their paper, this sort of social learning is sometimes called “culture.” Even if you’re living in a cave. 正如研究人員在他們的論文中指出的那樣,這種社會性的學習有時被稱為“文化”。即便是居住在山洞里的蝙蝠,這種文化依然存在。