2022年经济学人 动物们如何进行伪装?(2)（在线收听）

Joao Vitor de Alcantara Viana and colleagues from the State University of Campinas, in Brazil, compiled results from 84 studies on camouflage.

巴西坎皮纳斯州立大学的若昂·维托尔·德·阿尔坎塔拉·维亚纳和他的同事汇总了84项关于猎物伪装的研究结果。

They found that camouflage increased the amount of time a predator spent searching by over 60%, and it decreased the number of prey that were detected and attacked by around 25%.

他们发现，猎物的伪装导致捕食者寻找食物的时间增加了超过60%，被发现并受到攻击的猎物数量减少了约25%。

Masquerade (the dead leaf butterfly, for example) was the most effective technique, nearly quadrupling the time predators spent searching.

假扮(例如枯叶蛱蝶)是最有效的战术，能够让捕食者寻找猎物时间变为原来的四倍。

Eyespots on butterfly wings seemingly provided no benefits in terms of hiding time from predators, but Mr. Alcantara noted that this was not surprising since that tactic is not meant to interfere with detection, but rather to reduce the lethality of an attack.

蝴蝶翅膀上的眼点在躲避捕食者方面似乎没有任何作用，但阿尔坎塔拉先生指出，这是很正常的，因为眼点并不是为了干扰捕食者探测，而是为了降低其攻击的杀伤力。

Camouflage need not be visual.

伪装不一定是视觉上的伪装。

Bats, for example, perceive the world through sound.

例如，蝙蝠通过声音感知世界。

Some of the moths they predate have therefore evolved a "stealth coat" - made of tiny hairs and a layer of scales - that reduces their detectability through echolocation.

因此，它们捕食的一些蛾子进化出了一种“隐形皮毛”——由微小的毛发和一层鳞片组成——降低了它们在蝙蝠的回声定位中被探测到的可能性。

Marc Holderied, a biologist at the University of Bristol, wanted to know how good the moths were at hiding from bats so he shaved off their hairs and then sent sound waves towards them, mimicking how bats might echolocate to find their prey.

布里斯托尔大学的生物学家马克·霍尔德里德想知道飞蛾躲避蝙蝠的能力有多强，所以他剃掉了飞蛾的毛，然后向它们发送声波，模仿蝙蝠寻找猎物时的回声定位。

The moths' one-and-a-half-millimetre layer of fur, it turned out, reduced their detectability by just over 40%.

事实证明，有一层半毫米毛皮的飞蛾被探测的可能性降低了超过40%。

In addition to the fur, moths also have a thin layer of scales, tens to hundreds of thousands of them, on each wing.

除了毛皮，飞蛾的每只翅膀上都有一层薄薄的鳞片，数量从数万到数十万片不等。

The scales each respond to specific frequencies of sound waves and when a bat's echolocation signals hits the moth's wings, the scales start to vibrate.

每片鳞片都会对特定频率的声波做出反应，当蝙蝠的回声定位信号击中飞蛾的翅膀时，鳞片开始振动。

The acoustic energy from the echolocation is thus absorbed.

这样，回声定位产生的声能就会被吸收。

Dr. Holderied and his colleagues tested how well the scales worked and found that they were just as good at absorbing sound as the fur - they absorbed as much as 87% of the incoming sound energy, but at only one tenth of the fur's thickness.

霍尔德里德博士和他的同事们测试了鳞片的工作情况，发现它们在吸收声波方面效果与毛皮一样好——它们能够吸收高达87%的传入声能，但其厚度只有毛皮的十分之一。

In terms of their ability to absorb sounds, Dr. Holderied says the moth's scales outperform (and are much thinner than) any human-designed soundproofing used in homes and offices.

霍尔德雷德博士表示，就吸收声波的能力而言，飞蛾的鳞片比任何家庭和办公室使用的人类设计的隔音材料都要好得多(也要薄得多)。

Camouflage not only provides a backdoor into glimpsing the magnificently diverse sensory worlds of animals, it has also inspired intriguing applications for people.

伪装不仅提供了一扇窗，让人们得以一窥动物多姿多彩的感官世界，还启发人们进行有趣的创作。

Artists and anti-technology activists have invented make-up techniques, for example, known as "computer vision dazzle" that take their cues from natural camouflage and work by drawing high-contrast contours and colourful shapes on human faces so that they can evade detection by computer facial recognition.

例如，艺术家和反科技活动人士发明了被称为“计算机视觉眩晕”的化妆技术，从自然界的伪装中获取灵感，在人脸上绘制高对比度的轮廓和五颜六色的花纹来逃避计算机的面部识别。

And Dr. Holderied's team has been taking inspiration from the miraculously sound-absorbing properties of moths to design wallpaper that can reduce the noise of road traffic for the occupants of a building.

霍尔德雷德博士的团队一直在从飞蛾神奇的吸音特性中获取灵感，设计能够为居民降低道路交通噪音的墙纸。

Though evolved in nature, camouflage can be useful in modern city life, too.

虽然伪装是自然界进化的产物，但也能用于现代城市生活。