全球气候变暖 北极熊被迫改变捕猎方式

This is Scientific American’s 60-Second Science. I’m Fionna Samuels.

这里是科学美国人——60秒科学系列，我是菲奥娜·塞缪尔。

The life of a polar bear is hard.

北极熊的生活很艰难。

It’s made even harder as temperatures climb.

随着气温的上升，变得更加困难。

The bears of the north largely depend on sea ice to survive, hunting seals that take a breath through gaps in the ice.

北极熊在很大程度上依靠海冰生存，猎杀通过冰缝喘口气的海豹。

For most bears, their feeding opportunities disappear as sheets of sea ice melt.

对于大多数北极熊来说，随着片片海冰的融化，它们的进食机会消失了。

Now researchers have identified a new subpopulation of polar bears that may be able to survive longer thanks to their ability to use glacial ice as a sea ice alternative.

现在，研究人员已经发现了一个新的北极熊亚群，由于它们能够利用冰川冰替代海冰，它们可能会存活更长时间。

I’ve been working on polar bears for about 15 years, and this particular study was just really a wholly unexpected finding that came out of a much larger survey of polar bears along the east coast of Greenland.

我已经研究北极熊有15年了，这项特殊的研究是一个完全出人意料的发现，而这一发现来自于对格陵兰东海岸北极熊的一项更大规模的调查。

That’s Kristin Laidre a marine biologist at the University of Washington in Seattle who was part of the team of scientists who spent years tracking polar bears in Greenland.

这是西雅图华盛顿大学的海洋生物学家克里斯汀·莱德雷，他是在格陵兰追踪北极熊多年的科学家团队中的一员。

They recently published their surprising findings in a paper in Science.

他们最近在《科学》期刊上发表了一篇惊人的发现。

We lay out the evidence for a previously undocumented and highly isolated subpopulation of polar bears living on the southeast coast of Greenland.

我们列出了从未有过记录的、高度孤立的北极熊亚群(它们生活在格陵兰东南海岸)的证据。

We knew you could find polar bears in that area, but we just didn’t think there were that many, because it’s not really a place, you'd expect a lot of bears or bears to be able to persist for very long.

我们知道你可能在那个地区找到北极熊，但我们只是没有想到会有那么多只北极熊，因为这不是一个预计能让很多北极熊存活很久的地方。

Basically—the area wasn’t expected to be particularly bear-friendly because it goes long periods of time without sea ice.

基本上--预计这个地区不会特别适合熊生存，因为该地区很长一段时间没有海冰。

Generally, polar bears will starve if there are more than 100 sea-ice-free days during the year because they primarily rely on sea ice to hunt for seals and other prey.

一般来说，如果一年中有100多天没有海上浮冰，北极熊就会饿死，因为它们主要依靠海冰来捕食海豹和其他猎物。

But these bears can supplement the sea-ice-free days with glacial ice.

但这些北极熊可以用冰川冰来替代没有海冰的日子。

We realized that this glacial ice was essentially supporting an isolated population.

我们意识到，这些冰川冰基本上是在养活孤立的北极熊种群。

So it wasn’t just they were using it, you know, opportunistically;

北极熊不仅仅是见机行事地利用冰川冰，

it was that the only way these bears would live in this isolated place and be isolated for hundreds of years with such a short sea ice season is to take advantage of this glacial ice and really rely on it for survival.

在如此短的海冰季节，这些熊能在这个孤立的地方生活几百年的唯一方法就是利用冰川冰，真正依靠冰川冰来生存。

This adaptation may help these polar bears hang on longer than their distant neighbors who rely on sea ice.

这种适应可能有助于这些北极熊比依赖海冰生存的远亲邻居坚持更长时间。

It’s a hopeful story, in the sense of “We found this new group of bears.”

从“我们发现了这群新的熊”的意义上讲，这是一个充满希望的故事。

We didn’t know about them, you know; they add this genetic diversity.

我们不了解这群北极熊，它们增加了遗传多样性。

You know, it has to also be presented in the context of the whole Arctic, and what we see we’re headed for, and you know, the fact that all polar bears don’t have this option—and most don’t.

在整个北极的背景下，这不得不呈现出来，我们所看到的事实是，所有的北极熊都没有这种选择——大多数都没有。

As climate change brings us closer to an ice-free arctic, this group of polar bears may help scientists understand how the species might persist.

气候变化让我们更接近无冰的北极，这群北极熊可能会帮助科学家理解北极熊物种如何继续生存。

Those that persist might look a lot like this subpopulation, living in similar environmental pockets.

那些存活下来的北极熊可能看起来很像这个亚群，它们生活在有相似环境的孤立地区。

If we can monitor these bears for the next 10, 20, 30 years, we’re going to learn a lot about how they do in an Arctic that continues to warm.

如果我们能在接下来的10年、20年或30年里监测这些北极熊，我们将会了解它们在持续变暖的北极是如何生存的。

But in the end, saving polar bears really comes down to one thing.

但归根结底，拯救北极熊实际上归结为一件事。

If we care about polar bears, global climate action is the most important thing that we can do.

如果我们关心北极熊，全球气候行动是我们能做的最重要的事情。

For Scientific American’s 60-Second Science, I’m Fionna Samuels.

谢谢大家收听科学美国人——60秒科学。我是菲奥娜·塞缪尔。