Tracking grizzly bears from space - David Laskin

Transcriber: Andrea McDonough Reviewer: Jessica Ruby

翻译人员: Mengyu Zheng 校对人员: Chen Zou

These are grizzly bears.

这些是灰熊

As you can see, they have big teeth and giant claws.

如你所见，它们有巨大的牙齿和下颚

But once you get to know them better,

但是如果你进一步地了解它们

they're not as ferocious as you might think.

它们并没有你想象的那么凶残

They play a critical role in the function of our ecosystems,

它们在我们的生态系统中扮演着重要的角色

but, unfortunately, their habitat is dwindling fast.

然而不幸的是，它们的栖息地正在迅速减少

In order to protect them,

为了保护它们

it's important to know

我们必须了解

why do grizzlies choose certain areas

为什么灰熊会选择某些特定的地区

to inhabit in the first place?

作为它们一开始的栖息地呢？

Let's look at a threatened population of bears

我们来看看这一群受到威胁的熊

living in the rocky mountains of Canada.

它们生活在加拿大的落基山脉

Remember those giant claws?

还记得那些巨大的爪子吗？

Well, they're not for what you might think.

这爪子可能跟你想的不太一样

They have evolved specifically

它们经过了具体的进化

for digging up energy-rich roots.

专门用于挖出热量丰富的根茎

It turns out that grizzlies eat a lot of plants.

原来灰熊会吃大量的植物

The ones that live here are almost vegetarians.

生活在这里的灰熊几乎都是素食动物

You see, unlike other predators,

你看，不像其它食肉动物

grizzlies have diverse diets

灰熊有更丰富多样的饮食

that can include up to 90% vegetation.

其中高达90%都是植物

However, maintaining a diet of plants can be difficult.

但是保持以植物为食并没有那么容易

In these northern latitudes, you have distinct seasons

这些北部地区有着分明的四季

where it's really nice and green for part of the year

一年中有些时候气候很好，绿意盎然

and really cold for the other part.

而其它时候却非常寒冷

If you eat plants, you have almost nothing to eat

如果你以植物为食，在寒冷的季节里

for the cold part of the year.

你几乎没什么东西可以吃

So, you either have to migrate like geese

所以，你要么像大雁一样迁徙

or hibernate like ground squirrels.

或者像地松鼠一样冬眠

Grizzly bears hibernate.

灰熊会冬眠

Their behaviors are closely synchronized with the seasons.

他们的行为与季节变化紧密地保持一致

During the summer, they have to pack on

在夏季，他们必须储存

enough body fat to survive the winter.

足够的身体脂肪，以度过冬天

Without it, they would either starve

没有这些脂肪，它们要么就挨饿

or not have enough energy

要么就没有足够的能量

to successfully produce offspring.

来成功繁衍后代

But when you eat mostly plants,

但是当你主要食用植物的时候

it's hard to gain a lot of weight.

想让体重大幅度增加是很难的

You need to be a highly effective forager.

你需要成为一个高效的采集者

So, bears tightly follow the schedule of the plants

所以，灰熊们非常严格地跟随着植物的生长周期

and harvest them like crops

像割庄稼一样

at the point in time when they are at the most nutritious.

在它们最有营养的时候采摘

This will happen in different places at different times.

这样的收割要在不同的地方和时间进行

In autumn, a large male grizzly can eat

在秋季，一头巨大的雄性灰熊

up to 200,000 berries in a single day.

一天可以吃掉高达200,000颗浆果

Therefore, to protect these bears,

因此，为了保护这些熊

researchers want to take a closer look

科学家们想更近距离地观察

at the seasonal interaction between grizzlies and plants

灰熊和植物之间季节性的相互影响

to identify areas of the highest quality habitat.

以便识别出最优质的栖息地

This begins 700 kilometers up in space.

他们先从700千米的高空开始

Up here, two NASA satellites carry sensors

这里，两颗NASA卫星携带着感应器

that are sensitive to the light reflected by vegetation.

可以检测出植被反射的光线

Every species of plant reflects

每种植物会反射出

a unique combination of wave lengths,

一个特殊的波长组合

called spectral signatures

这叫做光谱特征

that act like different chords on a piano

如同钢琴上不同的和弦

but use light instead of sound.

但是用光来代替声音

These signatures are recorded by the satellites every day

卫星每天记录下这些光谱特征

and are combined like frames in a movie

并将他们像电影框架一样合并

so you can watch the vegetation grow

这样你就能看到整个夏天里

over an entire summer.

植被的生长

Simultaneously, the movements of bears

与此同时，熊的移动轨迹

wearing GPS collars are monitored

由它们携带的GPS项圈来监测

to see how they respond to the ebb and flow

以观察它们对于栖息地中

of nutrition throughout their habitat.

食物养分流动和减退的反应

Now, instead of ordinary, static habitat maps,

现在，普通的静态栖息地图已经被取代

these dynamic, time-lapse habitat maps

而这些动态的，低速度的栖息地图

could be used for grizzly bear conservation

可以在各个方面

in a number of ways.

用于对灰熊的保护

First, they help calculate the carrying capacity

首先，它们可以帮助计算

of the study area.

指定地区的承载能力

In other words, how many bears

换句话说，余下的栖息地

can the remaining habitat support?

可以养活多少头灰熊？

Is there enough food to go around?

这里有足够的食物吗？

Second, the maps show

第二，这些地图可以显示出

where bears will be foraging at specific times.

在某个时间段中灰熊会在哪里采集食物

We can prevent disturbing the bears

我们可以避免惊扰这些灰熊

and stressing them out

使它们感到压力

by avoiding these areas during important feeding periods.

通过避免在重要的进食时间进入这些地区

Finally, the maps can be used

最后，这些动态地图可以用来

to predict the effects of climate change,

预测气候变化的影响

where shifting annual temperatures

因为每年的温度变化

will alter the rate of plant growth,

会改变植物的生长速度

throwing the bears' precise foraging schedule out of whack.

导致灰熊采集食物的精确时间表 被严重破坏

This provides less food

食物的供应减少

and increases competition between bears.

致使灰熊之间的竞争加剧

Grizzlies are charismatic symbols of the wilderness.

灰熊是荒野魅力的象征

These habitat maps made from satellite imagery

这些由卫星图像制成的栖息地图

can not only help conserve grizzly bears

不仅能够帮助保护灰熊

but all sorts of different species.

而且还能保护不同的物种

They aid us in understanding

这些地图能帮助我们理解

how ecosystems function,

生态系统如何运转

where they are threatened,

它们哪里受到了威胁

and how we can try to keep our fragile,

以及我们如何尽力维护

amazing planet intact.

我们脆弱而美好的星球