Are you familiar with the word symbiosis?

你知道互利共生（symbiosis）這個詞嗎？

It's a fancy term for a partnership between two different species,

意思是兩個物種之間的合作關係

such as bees and flowers.

蜜蜂和花，就是互利共生的例子

In a symbiosis, both species depend on each other.

兩者倚靠著對方生存

I want to tell you about a remarkable symbiosis

我有個很特別的例子想告訴你:

between a little bird, the Clark's Nutcracker,

一隻小鳥──北美星鴉

and a big tree, the Whitebark Pine.

和一棵大樹──白皮松之間的關係

Whitebark grow in the mountains of Wyoming, Montana and other western states.

白皮松生長在懷俄明州、蒙大拿州 等等美西地區

They have huge canopies and lots of needles,

它有巨大的樹冠層和滿布的針葉

which provide cover and shelter for other plants and animals,

能提供遮蔽和掩護給其他動植物

and Whitebark feed the forest.

也能滋養森林

Their cones are packed with protein.

白皮松的松果被蛋白質包覆著

Squirrels gnaw the cones from the upper branches

松鼠啃咬枝幹上層的松果

so they fall to the ground,

當松果落到地面

and then race down to bury them in piles, or middens.

松鼠就會衝下去把它們埋成好幾堆

But they don't get to keep all of them;

但是松鼠無法顧好每一堆松果

grizzlies and black bears love finding middens.

因為灰熊和黑熊會把它們挖出來

But there's more to a symbiosis than one species feeding another.

互利共生可不只是這樣而已

In the case of the Clark's Nutcracker, this bird gives back.

就北美星鴉來說，牠還會回饋

While gathering its seeds, it also replants the trees.

牠收集糧食之餘，還會替樹繁衍後代

Here's how it works: using her powerful beak,

牠怎麼做呢？ 就靠牠強壯的鳥喙

the Nutcracker picks apart a cone in a treetop,

北美星鴉會從樹梢叼走一顆松果

pulling out the seeds. She can store up to 80 of them in a pouch in her throat.

把種子從松果上啄下來，牠的頰囊最多能儲存80顆種子

Then she flies through the forest, looking for a place to cache the seeds

然後在森林中尋找適合的地方儲放種子

an inch under the soil in piles of up to eight seeds.

把每八顆種子種在一吋深的土壤裡埋成一堆

Nutcrackers can gather up to 90,000 seeds in the autumn,

北美星鴉能在一個秋天蒐集九萬顆種子

which they return for in the winter and spring.

牠們會在冬天和春天回去找種子

And these birds are smart. They remember where all those seeds are.

聰明如你，他們絕不會忘記種子被埋在哪裡

They even use landmarks on the landscape --

他們甚至能運用種子堆附近的地標

trees, stumps, rocks --

大樹、殘幹、岩石

to triangulate to caches buried deep under the snow.

連成一個三角形標記被深埋在雪中的種子

What they don't go back and get, those seeds become Whitebark.

會有幾堆種子沒被挖出來，那些種子就會長成白皮松

This symbiosis is so important to both species

這樣的互利共生對兩個物種是非常重要的

that they've changed, or evolved, to suit each other.

它們藉由改變、演化來滿足彼此

Nutcrackers have developed long, tough beaks

北美星鴉演化出又長又堅硬的喙

for extracting seeds from cones,

就為了要從松果上啄取種子

and Whitebarks' branches all sweep upwards

白皮松的枝幹往上延展

with the cones at the very ends, so they can offer them to the Nutcrackers as they fly by.

松果結在枝幹末端，就為了要讓北美星鴉飛來覓食

Now, that's a symbiosis:

這就是互利共生：

Two species cooperating to help each other for the benefit of all.

兩個物種間的相互合作且各取所需。 ─Translated by Jesse Chen 陳鉦翰