Karen Hopkin: This is Scientific American’s 60-Second Science. I’m Karen Hopkin.
这里是《科学美国人》的60秒科学。我是凯伦·霍普金。
Have you ever found yourself stuck in what felt like a never ending game of “stop copying me”…in which one person keeps repeating what the other one says? You probably figured that the person parroting you was just trying to be annoying. But some critters might use vocal mimicry to save their skins.
你有没有体验过一直被人学说话的无厘头玩笑?也就是有人一直模仿你,无休无止地重复你的动作和语言?你可能觉得TA这么做只是想惹恼你,但有些小动物可能会通过模仿声音来自保。
In a recent study, researchers found that certain bats buzz like bees…a sound that could discourage owls from eating them. The work appears in the journal Current Biology.
最近,研究人员发现某些蝙蝠会像蜜蜂一样嗡嗡叫,而这种声音可能会阻止猫头鹰吃掉它们。这项研究发表在《当代生物学》(Current Biology)杂志上。
Danilo Russo: The idea a dates back to over two decades ago.
这个想法可以追溯到二十多年前。
Hopkin: Danilo Russo is a professor of ecology at the University of Naples Federico Segundo in Italy.
达尼洛·鲁索是意大利那不勒斯费德里科塞贡多大学的生态学教授。
Russo: I was working for my PhD and I happened to capture some greater mouse-eared bats. When I took these bats out of the net, when I handled them, they invariably buzzed like wasps or hornets.
我正在攻读博士学位,碰巧捕捉到了一些更大的鼠耳蝙蝠。当我将这些蝙蝠从网中取出时,准备处理它们时,它们总是像黄蜂或大黄蜂一样嗡嗡作响。
[Bat buzzing]
[蝙蝠嗡嗡声]
Hopkin: But what was the point of this unusual auditory outburst? Was it an involuntary squeak of distress? A warning cry to fellow roost mates? Or maybe, Russo wondered, was it a clever attempt to trick potential predators into thinking that they might want to back off if they don’t want to wind up with a face full of bee stings?
但这种不寻常的突发性听觉攻击有什么意义呢?是一种不由自主的痛苦尖叫吗?还是为了警告同伴?鲁索猜想:这会不会是一种机智的尝试,为的是让潜在的捕食者认为,如果不想落得满脸蜇伤它们最好还是别靠近?
Russo: Of course, the idea was attractive, but it was not very easy to test. And it took me a long time to design the right experiment.
当然,这个想法很有吸引力,但测试起来并不容易。我花了很长时间来设计正确的实验。
Hopkin: The first thing the researchers did was compare the sounds made by mouse-eared bats with those made by hymenopterans…insects like bees and wasps.
研究人员做的第一件事是将鼠耳蝙蝠发出的声音与膜翅目昆虫,比如蜜蜂和黄蜂等昆虫发出的声音进行比较。
Russo: So we recorded four species of stinging hymenopterans in the field. As well as these buzzing bats in hand. And then we tested statistically whether these different buzzes could be similar enough to fool a predator.
我们在野外录下了4种带刺膜翅目昆虫的嗡嗡声,也录下了手中这些蝙蝠的模拟嗡嗡,然后对这些不同的嗡嗡声进行统计学测试,研究它们是否相似相似到足以迷惑捕食者。
Hopkin: And they found that the sounds were fairly similar. You already know what hornets sound like.
结果他们发现,这些嗡嗡声相似度极高。大黄蜂的嗡嗡声是这样:
[hornet buzzing]
[大黄蜂嗡嗡声]
Hopkin: And the bats do a pretty good job of replicating that ominous hum.
而蝙蝠们在模仿这种不祥的嗡嗡声上做得很好:
[bat buzzing]
[蝙蝠嗡嗡声]
Hopkin: But even more interesting…when the researchers filtered the audio to include only the frequencies that can be heard by owls…the bats’ main predator…the soundprints were even more alike.
但更有趣的是,当研究人员对音频进行频率过滤,使其只包含猫头鹰(鼠耳蝠的主要捕食者)可以听到的频率时,两类嗡嗡声的声纹变得更相似了……
Russo: Of course this was just the first step. But then we had to see how an owl would react to these sounds.
当然,这只是第一步,接下来我们得看看猫头鹰会对这些声音做出什么反应。
Hopkin: Working with an avian rescue center, Russo and his colleagues exposed 8 barn owls and 8 tawny owls to the buzzy output of both bees and bats and they recorded the birds’ reactions.
鲁索和同事与一家鸟类救援中心进行了合作,给8只仓鸮和8只西灰林鸮播放了蜜蜂和蝙蝠发出的嗡嗡声,并记录了这些猫头鹰的反应。
Russo: In all such cases it was nice to see that the owls actually stepped back. So it increased the distance from the sound source, ok, which was identified as a potential danger.
让我们很高兴的是,每种声音都让猫头鹰们不禁后退,它加大了与声源的距离,也就是它们认为这些声音是一种潜在的危险
Hopkin: So, the birds backed away from the buzz. But what if owls just aren’t fond of noise in general? To test that out, the researchers conducted a control experiment, in which they broadcast some non-buzzy bats sounds.
鸟儿们的确避开了这些嗡嗡声,但如果猫头鹰就是单纯地不喜欢噪音呢?为了对这一可能性进行测试,研究人员还进行了一项对照实验:给这些猫头鹰播放一些不是嗡嗡声的蝙蝠声音。
Russo: And in that case the reaction of the owl was completely opposite. Because the owl started to inspect the origin of the sounds. Probably because it was taken as a clue that a potentially tasty prey item was there.
在那种情况下,猫头鹰的反应完全相反,它们开始探查声音的来源,可能是因为它们将这些声音视为潜在美味猎物存在的线索。
Hopkin: Interestingly, owls who were older when they were taken in by the rescue center were more perturbed by the cautionary buzzing than were birds that had been taken in as chicks.
有趣的是,在年龄较大时才被救援中心收留的猫头鹰,比从小鸟时期就被收留的猫头鹰更容易受到警示性嗡嗡声的干扰。
Russo: This makes perfect sense because adult animals that had experienced the danger posed by stinging hymenopterans in the field will think twice before approaching a buzzing sound. While of course na?ve owls would not have this experience and would not rely on it.
这完全解释得通,因为在野外经历过膜翅目昆虫叮咬所带来的危险的年长猫头鹰,会在接近嗡嗡声之前三思而后行;而涉世不深的猫头鹰们则不具备这样的经验,也不会有所顾忌。
Hopkin: The study was the first to find acoustic mimicry between a mammal and an insect. But based on the positive buzz, it probably won’t be the last.
这是研究人员首次发现哺乳动物和昆虫之间存在声学??模仿,但基于研究的正面结果,这应该不会是最后一次。
For Scientific American’s 60-Second Science, I’m Karen Hopkin.
以上是《科学美国人》的60秒科学,凯伦·霍普金报道。
Karen Hopkin: This is Scientific American’s 60-Second Science. I’m Karen Hopkin.
Have you ever found yourself stuck in what felt like a never ending game of “stop copying me”…in which one person keeps repeating what the other one says? You probably figured that the person parroting you was just trying to be annoying. But some critters might use vocal mimicry to save their skins.
In a recent study, researchers found that certain bats buzz like bees…a sound that could discourage owls from eating them. The work appears in the journal Current Biology.
Danilo Russo: The idea a dates back to over two decades ago.
Hopkin: Danilo Russo is a professor of ecology at the University of Naples Federico Segundo in Italy.
Russo: I was working for my PhD and I happened to capture some greater mouse-eared bats. When I took these bats out of the net, when I handled them, they invariably buzzed like wasps or hornets.
[Bat buzzing]
Hopkin: But what was the point of this unusual auditory outburst? Was it an involuntary squeak of distress? A warning cry to fellow roost mates? Or maybe, Russo wondered, was it a clever attempt to trick potential predators into thinking that they might want to back off if they don’t want to wind up with a face full of bee stings?
Russo: Of course, the idea was attractive, but it was not very easy to test. And it took me a long time to design the right experiment.
Hopkin: The first thing the researchers did was compare the sounds made by mouse-eared bats with those made by hymenopterans…insects like bees and wasps.
Russo: So we recorded four species of stinging hymenopterans in the field. As well as these buzzing bats in hand. And then we tested statistically whether these different buzzes could be similar enough to fool a predator.
Hopkin: And they found that the sounds were fairly similar. You already know what hornets sound like.
[hornet buzzing]
Hopkin: And the bats do a pretty good job of replicating that ominous hum.
[bat buzzing]
Hopkin: But even more interesting…when the researchers filtered the audio to include only the frequencies that can be heard by owls…the bats’ main predator…the soundprints were even more alike.
Russo: Of course this was just the first step. But then we had to see how an owl would react to these sounds.
Hopkin: Working with an avian rescue center, Russo and his colleagues exposed 8 barn owls and 8 tawny owls to the buzzy output of both bees and bats and they recorded the birds’ reactions.
Russo: In all such cases it was nice to see that the owls actually stepped back. So it increased the distance from the sound source, ok, which was identified as a potential danger.
Hopkin: So, the birds backed away from the buzz. But what if owls just aren’t fond of noise in general? To test that out, the researchers conducted a control experiment, in which they broadcast some non-buzzy bats sounds.
Russo: And in that case the reaction of the owl was completely opposite. Because the owl started to inspect the origin of the sounds. Probably because it was taken as a clue that a potentially tasty prey item was there.
Hopkin: Interestingly, owls who were older when they were taken in by the rescue center were more perturbed by the cautionary buzzing than were birds that had been taken in as chicks.
Russo: This makes perfect sense because adult animals that had experienced the danger posed by stinging hymenopterans in the field will think twice before approaching a buzzing sound. While of course na?ve owls would not have this experience and would not rely on it.
Hopkin: The study was the first to find acoustic mimicry between a mammal and an insect. But based on the positive buzz, it probably won’t be the last.
For Scientific American’s 60-Second Science, I’m Karen Hopkin.
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