科学美国人60秒 气候变化会使鸟类的大脑缩小(1)

This is Scientific American’s 60-Second Science. I’m Shahla Farzan.

这里是科学美国人——60秒科学系列，我是沙拉·法尔赞。

Climate change is affecting animals in a lot of different ways.

气候变化正在以许多不同的方式影响动物。

But scientists have noticed a common trend across a variety of species: they’re getting smaller. As in—physically smaller in size.

但科学家们注意到了各种物种的一个共同趋势：它们正在变得越来越小。在体型上变得更小。

But why, and what could this mean?

这可能意味着什么呢？

Scientists have observed this phenomenon in very different animal species from wild sheep to woodrats.

科学家在不同的动物物种中(从野生绵羊到林鼠)观察到了这种现象。

But it’s especially well-documented in North American songbirds.

但这种现象在北美鸣禽中的证据尤其充分。

In 2019, researchers at the University of Michigan published a dataset of more than 70,000 birds that died after hitting windows in Chicago.

2019年，密歇根大学的研究人员发布了一个超过7万只鸟的数据集，这些鸟都是在芝加哥撞到窗户后死亡的。

The data showed the body sizes for dozens of species had actually shrunk over the past 40 years.

数据显示，在过去的40年里，数十个物种的身体尺寸实际上都缩小了。

But when Justin Baldwin, a graduate student at Washington University in St. Louis, took a closer look at the data, something stood out.

但当圣路易斯华盛顿大学的研究生贾斯汀·鲍德温仔细研究数据时，有些东西脱颖而出。

There clearly seem to be some species that were shrinking a lot and other species that were shrinking much less.

显然，似乎有一些物种的体型减少了很多，而其他物种体型减少要少得多。

The question was why were some bird species shrinking faster than others?

问题是为什么一些鸟类物种比其他物种变小的速度更快？

Baldwin and his colleagues had a feeling that bird behavior might be playing a role.

鲍德温和他的同事们有一种感觉，鸟类的行为可能在其中发挥了作用。

In birds, species with bigger brains tend to be smarter and can change their behavior based on their environment.

在鸟类中，大脑更大的物种往往更聪明，而且可以根据环境改变自己的行为。

That means that they might be able to buffer themselves from increasing temperatures, says Carlos Botero, an assistant professor of biology at Washington University and the study’s co-author.

华盛顿大学生物学助理教授、这项研究的合著者卡洛斯·博特罗表示，这意味着它们或许能够缓解气温上升的影响。

By adjusting their behavior, by changing the places that they look for food, the times of the day in which they do that, the things that they eat, and the ways in which they access those food sources.

通过调整它们的行为，通过改变它们寻找食物的地方，改变它们寻找食物的时间，改变它们吃的东西，以及它们获得这些食物来源的方式。

All those are ways in which they could experience a little bit less of a negative selection from all this variety of changes that we're seeing through climate change.

在所有这些方式中，它们可以从我们通过气候变化所看到的各种变化中少经历一些负面选择。

A bigger-brained bird, for example, might adjust its behavior and stay in the shadows when it’s hot.

例如，大脑较大的鸟可能会调整自己的行为，在天气炎热时呆在阴影中。