No cattle could survive here. So for centuries, reindeer has been domesticated by Scandinavia's only indigenous people - the Saami.
牛群无法在此生存，所以几个世纪以来，斯堪的纳维亚地区唯一的本地居民一萨米人，始终在驯养驯鹿。
The Saami have adopted some modern technologies, but reindeer remain in the heart of every aspect of life.
尽管萨米人如今也采用了一些现代科技，但驯鹿仍然在他们各方面生活中处于核心地位。
They've relied on the reindeer for the last ten thousand years.
他们己经依靠驯鹿生活了一万年。
They are Europe's last remaining nomads and building a life around the reindeer's migration has made living in the tundra viable.
它们是如今欧洲仅存的最后一个游牧民族，而利用驯鹿迁徙建立的生活方式使得在苔原上生活变为可能。
The Saami use the reindeer for everything, from food and clothing to the tents they live in.
萨米人利用驯鹿做各种东西，从食物和衣着到他们居住的帐篷。
Even domesticated reindeer migrate and food is not the only reason they're heading north.
即使被驯化的驯鹿也会迁徙，而食物并不是它们向北迁徙的唯一原因。
It's their natural urge to give birth in the land where they themselves were born that drives the herd northwards into the harsh conditions of the tundra.
要在它们自己的出生地繁衍后代的自然本能驱使着驯鹿群向北进入环境恶劣的苔原地带。
Following the reindeer's natural migration route is what allows the Saami to live this far north.
跟随驯鹿的自然迁徙路径是萨米人得以在如此极北部的地区生存的诀窍。
But the journey made by the wild reindeer with the North American tundra is on the different scale.
然而北美洲苔原上野生驯鹿群的迁徙之旅规模上却是截然不同的。
Over three million wild reindeer migrate across the tundra.
超过三百万头的野生驯鹿加入到穿越苔原的迁徙之旅。
This herd of over one hundred thousand makes the longest migration of any land animal.
这群十万之众的驯鹿迁徙的旅程是所有陆地动物中最长的。
Known as the porcupine herd, each year, they travel up to five thousand kilometers.
它们被称为格兰特驯鹿，每年要迁徙长达五千公里的路程。
Once they leave the shelter of the trees, the reindeer are more vulnerable to predators.
驯鹿们一旦离开了树林的庇护就更容身遭到掠食者的攻击。
But they can run at speeds up to eighty kilometers an hour.
不过它们的奔跑速度可达每小时八十公里。
The reindeer is also one of the only mammals on the planet that can see ultraviolet light.
驯鹿还是为数不多的能看到紫外线的哺乳动物之一。
And in the tundra, that means the fur of any predator appears black against the landscape.
而在苔原上，这就意味着任何掠食者的毛皮在环境映衬下都显现为黑色。
The abundance of reindeer attracts one of the deadliest killers on the planet - the gray wolf.
数量众多的驯鹿吸引了一种地球上最致命的掠食者-灰狼。