科学美国人60秒 SSS 虎蛾是逃离还是面对蝙蝠要取决于其毒性（在线收听）

This is Scientific American's 60-second Science, I'm Susanne Bard.

这里是科学美国人——60秒科学系列，我是苏珊娜·巴德。

About 12,000 species of tiger moth exist on Earth. Some of them swoop and dive out of harm's way when a hungry bat tries to make them a meal. But other tiger moth species are more blasé—they just don't bother to flee from the hungry bats.

地球上大约有12000种虎蛾。当饥饿的蝙蝠试图捕食虎蛾时，其中一些虎蛾会突然俯冲到安全地方。但其它种类的虎蛾却无动于衷——它们只是懒得逃避饥饿的蝙蝠。

"And I really just wanted to know why. Why the difference? What factors might be influencing whether a species is more or less likely to perform these evasive maneuvers?"

“我真的想知道原因。为什么会有这种差异？哪些因素可能会影响虎蛾更愿意或更不愿意实施逃避行为？”

Wake Forest University behavioral ecologist Nick Dowdy. He says it's a matter of taste—some of the moths are delicious, but others are toxic and taste terrible. When the airborne predators catch these unappetizing moths, they'll spit them out, giving the insects a new lease on life.

维克森林大学的行为生态学家尼克·道迪说到。他说这与口味有关，有些蛾子的味道很美味，但其它则有毒，而且味道很糟糕。飞行中的捕食者捉到这些倒胃口的蛾子时，会把它们吐出来，让蛾子重获新生。

In a field experiment, Dowdy and his colleague William Conner filmed how five different species of tiger moths responded to bat attacks.

在现场实验中，道迪及同事威廉·康纳拍摄了五种不同种类的虎蛾面对蝙蝠攻击时的反应。

"And what we found was that those species which were really toxic—so when the bats captured them, they almost never ate them—those species were much more likely to be what we call nonchalant, species that do not perform evasive maneuvers very often. On the other hand, species that were really palatable were much more likely to perform those evasive maneuvers, almost, in a sense, sort of h?edging their bets. Because if they don't make that escape, if they are captured by a bat, those species are more likely to be eaten."

“我们发现，真正有毒的那些虎蛾，蝙蝠捉到它们时几乎从不吃掉它们，这些虎蛾更有可能是我们所说的漠不关心的物种，它们不常实施逃避行为。另一方面，真正美味可口的虎蛾更可能实施逃避行为，在某种意义上，这可以算是两面下注。因为如果它们逃走，如果被蝙蝠抓住，它们就更有可能被吃掉。”

Another factor is that evasive maneuvers have their own set of risks, which may be why unpalatable moths tend to avoid them. For example, diving away from bats burns fuel, gives the insects less time to seek out mates and could expose them to other perils, such as getting stuck in water.

另一个因素是，逃跑策略本身也存在一系列风险，这可能就是为什么难吃的虎蛾选择逃避的原因。例如，潜入水中逃离蝙蝠会消耗能量，减少其寻找配偶的时间，并可能使它们面临其他危险，比如被困在水中。

"Or there could be predators on the ground like mice and other mammals."

“或者地面上可能有老鼠和其它哺乳动物等捕食者。”

The study is in the journal Frontiers in Ecology and Evolution.

这项研究发表在《生态学与进化前沿》期刊上。

Dowdy is now trying to identify the chemical compounds responsible for making some tiger moths taste bad. Once those findings are in, chemical analysis of museum specimens could help reveal how rare, endangered or even extinct insects have behaved around predators.

道迪现在正试图找出导致某些虎蛾变得难吃的化合物。一旦相关发现出炉，对博物馆标本进行化学分析将有助于揭示稀有、濒危甚至灭绝昆虫在捕食者周围的行为方式。

"We can still study animal behavior even without a living organism. That's, I think, pretty amazing."

“即使没有活体有机物，我们仍可以研究动物的行为。我觉得这真是太棒了。”

Other animals with conspicuous warning signals, such as garishly colored poison dart frogs and foul-smelling skunks are also known to be slow movers. Perhaps if you're deadly, toxic or just plain stink, it can pay to be lazy.

其它有明显警告信号的动物，如七彩斑斓箭毒蛙和气味难闻的臭鼬，也被认为是行动迟缓的动物。也许，如果你具备致命能力，有毒或者仅仅是臭气熏天，那你可以选择懒惰。

Thanks for listening for Scientific American's 60-second Science. I'm Susanne Bard.

谢谢大家收听科学美国人——60秒科学。我是苏珊娜·巴德。