人类让野生动物变得不那么警觉

This is Scientific American's 60-second Science, I'm Jason Goldman.

这里是科学美国人——60秒科学系列，我是杰森·戈德曼。

Wild animals are equipped with a variety of techniques to avoid becoming lunch for a bigger, toothier animal.

野生动物有各种各样的技巧来避免成为块头更大和牙齿更多的动物的午餐。

The most well-known methods include the classic “fight” and “flight,” as well as “freeze.”

最著名的方法包括经典的“战斗”、“逃跑”和“僵住反应”。

A team of researchers wondered how proximity to people might impact those survival strategies.

一组研究人员想知道与人亲近会如何影响这些生存策略。

“We often see that animals are more tolerant around us in urban areas, but we don't really know why.”

“我们经常看到城市里的动物对我们更宽容，但我们真的不知道为什么。”

U.C.L.A. evolutionary biologist Dan Blumstein.

加州大学洛杉矶分校进化生物学家丹·布鲁姆斯坦。

“Is it a filtering process where only the tolerant animals are there? Is it individual plasticity, meaning individuals change their fear of us, and that leads to tolerance? Or can there be an evolutionary dynamic occurring?”

“这是一个过滤过程，只有宽容的动物在那里吗? 是个体的可塑性，即个体改变了他们对我们的恐惧，从而导致了宽容吗? 或者还是会发生进化动态?”

To find out, Blumstein and colleagues combined information from 173 studies of more than 100 species, including mammals, birds, reptiles, fish and even mollusks.

为了找到答案，布鲁姆斯坦和他的同事综合了来自100多种物种的173项研究的信息，包括哺乳动物、鸟类、爬行动物、鱼类甚至软体动物。

Turns out that regardless of evolutionary lineage, the animals react in a similar way to life among humans: they lose their antipredator traits. That pattern is especially pronounced for herbivores and for social species.

事实证明，不管进化谱系如何，这些动物对人类生活的反应是相似的:它们失去了反捕食者的特征。 这种模式在食草动物和群居物种中尤为明显。

This behavioral change is perhaps unsurprising when it’s intentional, the result of domestication and a controlled breeding paradigm.

当这种行为变化是驯养和控制繁殖范式的结果时，它是有意的，也许并不令人惊讶。

But it turns out that urbanization alone results in a similar change, though much more slowly—around three times more slowly.

但事实证明，城市化本身也会导致类似的变化，尽管速度要慢得多——大约是城市化速度的三倍。

The results are in the journal PLOS Biology.

研究结果发表在《公共科学图书馆·生物学》杂志上。

“The main point is: we’re essentially domesticating animals by urbanization.

“重点是:我们基本上是通过城市化来驯化动物的。

We’re selecting for the same sorts of traits that we would if we were actually trying to domesticate them.”

如果我们真的试图驯化它们，我们正在选择相同类型的特征。”

If the urbanization process helps animals better coexist with people, it could be to their benefit.

如果城市化进程有助于动物与人类更好地共存，这可能对它们有利。

But if it makes them more vulnerable to their nonhuman predators, it could be a real problem.

但如果这让它们更容易受到非人类捕食者的攻击，那就真的有问题了。

Either way, these results mean that city living exerts enough of an influence on wild animals that evolutionary processes kick in.

无论如何，这些结果意味着，城市生活对野生动物产生了足够的影响，进化过程开始发挥作用。

Those reductions in antipredator traits become encoded in their genes.

这些反捕食者特征的减少被编码在他们的基因中。

“We’re changing the population genetics and changing genetic variation. We are reducing, we are eliminating variation. And if variation is a good thing and is a target of conservation, then that’s something to be concerned with.”

“我们正在改变种群遗传学和遗传变异。我们正在减少，我们正在消除变化。如果变异是一件好事并且是保护的目标，那么这就是值得关注的事情。”

What the researchers now wonder is whether the mere presence of tourists in less urbanized areas can instigate similar changes in wild animals.

研究人员现在想知道的是，在城市化程度较低的地区，仅仅是游客的出现，是否就会在野生动物中引发类似的变化。

If so, serious questions exist for the notion of ethical, welfare-oriented ecotourism.

如果是这样，那么以道德和福利为导向的生态旅游的概念就存在严重的问题。

If we wish to help animals retain their antipredator defenses, the researchers say, we might have to intentionally expose animals to predators—or at least to predator-related cues.

研究人员说，如果我们希望帮助动物保持它们的反捕食防御，我们可能必须有意地让动物接触捕食者——或者至少接触与捕食者相关的线索。

“It’s just yet one other way that we’re changing the world around us.”

“这只是我们改变周围世界的另一种方式。”

Thanks for listening for Scientific American's 60-second Science. I'm Jason Goldman.

谢谢大家收听科学美国人——60秒科学。我是杰森·戈德曼。