科学美国人60秒 SSS 别忘了退后一步看问题（在线收听）

Animal Coloration Can Serve Double Duty

Nature may be red in tooth and claw. But one plucky caterpillar dresses in orange and black to avoid becoming somebody’s lunch. What’s really surprising, though, is that this distinctive set of stripes can serve as both a warning or as camouflage, depending on how far away it is from the viewer.

大自然中可能有红色的牙齿，红色的爪子。甚至一只毛毛虫也“穿着”橙、黑色相间的衣服以免成了别人的口中之食。但真正令人惊讶的是，这种独特的条纹可以作为警告或伪装，而这取决于它离观众有多远。

Animals can deploy color as a defense mechanism in a couple of ways. Some shades and patterns help potential prey blend into the background. Whereas bold markings often serve as a signal that an animal is unpalatable—for example, chock full o’ toxins.

动物可以通过几种方式将色彩变为防御机制。比如一些阴影和图案可以帮助潜在的猎物融入背景里。但是大胆的标记通常是此动物不可食的信号如，身上满是毒素的标记。

“So, these two strategies have often been considered in isolation and often seen as mutually exclusive and alternative mechanisms. But under natural conditions you find this distinction is less clear cut.”

因此，这两种战略并不会同时出现，通常是两者择其一。但是但实际自然条件下，你会发现这两种的区别不太明显。

Jim Barnett of the University of Bristol, who led the study to explore whether the same coloration might do double duty, allowing an animal to be obvious under some conditions but unseen in others.

布里斯托尔大学的Jim Barnett领导了这项研究，他研究了同样的颜色是否可以起到双重作用，让动物在某些条件下变得明显，而在另一些情况下却不易被看到。

They focused their attention on the caterpillars of cinnabar moths. These larvae sport bright orange and black stripes. Their vivid appearance was believed to remind the birds who may have eaten others of their kind that they are none too tasty, thanks to their diet of alkaloid-rich ragwort plants.

他们把注意力集中在毛虫身上。这些幼虫具有明亮的橙色和黑色条纹。它们的生动形象可能是为了提醒那些可能吃过其他同类的鸟类，自己并不好吃，因为它们的食物中含有丰富的碱的雷舌草植物。

The researchers snapped photos of the caterpillars in suburban green spaces around Bristol. And they used a visual modeling program to give them a “bird’s-eye view” of what the caterpillars look like, either close-up or from farther away.

研究人员拍下了布里斯托尔郊区绿地上的毛虫的照片。他们用一个可视化的建模程序给他们鸟类提供了一个“鸟瞰”的视角，即毛毛虫的样子，要么是特写，要么是离得更远。

“And what we found is that although at close range the caterpillar’s stripes are highly conspicuous—these bright colors distinguish it quite easily from its ragwort background—but when viewed from a distance they blend together to form a color which is actually quite difficult to discern from the background color. So, what we think is going on is that the caterpillar is getting the best of both worlds.”

我们发现，尽管在近距离的范围内，毛毛虫的条纹是非常显眼的——这些明亮的颜色很容易从背景中分辨出来，但从远处看，它们混合在一起形成了一种颜色，这实际上很难从背景颜色中辨别出来。所以，我们认是，毛毛虫无论是远观还是近看都得到了最好的结果。

Close up, the stripes say keep your distance. But from a distance, they allow the caterpillars to hide in plain sight. The results can be seen in the journal Royal Society Open Science.

靠近点，这些条纹会让你远离。但从远处看，它们让毛毛虫在普通的视线中躲藏。该项研究发表在《英国皇家学会开放科学》杂志上。

The finding is a reminder: Don’t forget to step back and see things from a different perspective.

这一发现提醒我们:别忘了退后一步，从不同的角度看问题。