Are you familiar with the word symbiosis?
你熟悉Symbiosis这个词（共生关系）吗？
It's a fancy term for a partnership between two different species, such as bees and flowers.
这是一个用来形容两个不同物种之间伙伴关系的美妙词汇，比如蜜蜂和花儿。
In a symbiosis, both species depend on each other.
在一个共生关系中，两个物种相互依赖。
I want to tell you about a remarkable symbiosis between a little bird,
我想要告诉你们一个很神奇的共生关系，建立于一只小鸟，
the Clark's nutcracker, and a big tree, the whitebark pine.
克拉克星鸦，和一棵大树，白皮松之间的关系。
Whitebark grow in the mountains of Wyoming, Montana and other western states.
白皮松生长于美国的怀俄明州，蒙大拿和其他西部各州的山区里。
They have huge canopies and lots of needles,
它们有巨大的顶篷和很多的针叶，
which provide cover and shelter for other plants and animals, and whitebark feed the forest.
为其他的灌木和动物提供了遮掩和保护，而且，白皮松可以为森林提供养料。
Their cones are packed with protein.
它们的球果拥有大量的蛋白质。
Squirrels gnaw the cones from the upper branches so they fall to the ground,
松鼠从它的上枝上咬掉球果，这样它们就掉落在了地上，
and then race down to bury them in piles, or middens.
然后，松鼠们就抢着去把它们埋在土堆或贝丘里。

But they don't get to keep all of them; grizzlies and black bears love finding middens.
但是松鼠们不能保存住所有的球果；灰熊和黑熊就爱找那些贝丘。
But there's more to a symbiosis than one species feeding another.
然而，共生关系远远不止于一个物种喂养另一个。
In the case of the Clark's nutcracker, this bird gives back.
就克拉克星鸦来说，这种鸟会给予回报。
While gathering its seeds, it also replants the trees.
当收集种子的同时，它也重新种植了树。
Here's how it works: using her powerful beak, the nutcracker picks apart a cone in a treetop, pulling out the seeds.
这就是它如何工作的：用它厉害的喙状嘴，星鸦从树尖上啄下一颗球果，拔出种子。
She can store up to 80 of them in a pouch in her throat.
它可以一次性在它的嘴里存上80颗种子。
Then she flies through the forest looking for a place to cache the seeds
然后它穿梭在森林里，寻找一个保存它的种子的地方。
an inch under the soil in piles of up to eight seeds.
它能在土下的一英寸的洞里存上9颗种子。
Nutcrackers can gather up to 90,000 seeds in the autumn, which they return for in the winter and spring.
星鸦能在一个秋天里收集上9万颗种子，以在来年的冬天和春天返回来寻找它们。
And these birds are smart. They remember where all those seeds are.
这些鸟非常聪明。它们能记住这些种子存放的地方。这些鸟非常聪明。它们能记住这些种子存放的地方。
They even use landmarks on the landscape -- trees, stumps, rocks -- to triangulate to caches buried deep under the snow.
它们甚至会利用地形和地貌--树木，残根，岩石--来三角定位到深埋在积雪里的存储处。
What they don't go back and get, those seeds become whitebark.
那些它们没有能回来收集的种子，它们就变成了白皮松。
This symbiosis is so important to both species that they've changed, or evolved, to suit each other.
这个共生关系对于双方物种是如此的重要，以至于它们改变或演化来相互适应对方。
Nutcrackers have developed long, tough beaks for extracting seeds from cones,
星鸦进化出了长长的、坚硬的喙形嘴，以从球果啄出种子，
and whitebarks' branches all sweep upwards with the cones at the very ends,
而白皮松的树枝都长成向上生长的，球果长在了最顶端，
so they can offer them to the nutcrackers as they fly by.
这样可以在星鸦飞越的时候提供给它们。
That's a symbiosis: Two species cooperating to help each other for the benefit of all.
这就是一个共生关系：两个不同的物种通过合作，为了大家共赢而相互帮助。