To some Arctic peoples, these northern lights are the spirits of dead seals, whales and caribou.
对北极的一些人来说，这些北极光是死了的海豹、鲸鱼和驯鹿的灵魂。
In fact, the aurora borealis is caused by storms on the sun.
而事实上，北极光是由太阳风暴引起的。
Huge plasma flares create solar winds that collide with our atmosphere.
大量的等离子光焰形成的太阳风和我们的大气层相撞。
These invisible energy streams get pushed towards the south and north poles.
这些看不见的能量流被地球磁场吸引到南北两极。
The result is nature's version of the neon light.
结果就产生了大自然的霓虹灯。
A single display can unleash as much electrical power as the United State's usage in a day.
极光单次放电就相当于美国一天的用电量。
Not many creatures are around to witness this spectacle.
不是很多生物都能目睹这一奇观。
Because Iceland is so isolated, it is home to surprisingly few animal species.
因为冰岛与世隔绝只有极少数几种动物在此安家。
Some birds have settled here together with a few rodent species imported by humans.
其中有一些鸟类，还有几种由人类引进的啮齿类动物。
The only native land mammal is the Arctic fox.
唯一的本土陆生哺乳动物是北极狐。
Its ancestors were stranded in Iceland at the end of the last Ice Age.
其祖先是上次冰河世纪末期被困在冰岛的。
Calmer weather gives the fox a chance to get on with the important business of finding food.
天气相对平静时，北极狐才有机会继续进行寻找食物的重任。
It's a resourceful hunter.
它可是个神通广大的猎手。
But winter means good meals are few and far between.
然而冬季里好吃的少之又少。
A Rock Ptarmigan might make a tasty snack.
岩雷鸟可能成为可口的小吃。
It's one of the few birds to remain inland during the freeze.
岩雷鸟是冰冻季节仍留在内陆的少数鸟类之一。
Feathered feet act as snow shoes.
长有羽毛的爪子就像是雪地鞋。
The Ptarmigan is a master of disguise.
雷鸟是伪装的高手。
Pure white plumage makes it all but invisible to the foxes.
纯白羽衣对狐狸来说几乎是隐身的。
Come spring when the snow melts, it will change to a mottled brown.
来年春天，当雪融化之时它会换上斑驳的褐色羽毛。
On the mainland, the vast majority of Arctic foxes also grow pure white winter coats.
大陆上绝大多数的北极狐也都穿纯白色的冬装。
But this isolated island population is different.
但这一孤岛上的群体却与众不同。
With no natural predators, there is little need for winter camouflage.
因为没有天敌，冬季的伪装就没有多大必要。
This could be a clue as to why most foxes here maintain their dark color all year long.
这可能也解释了为什么这里大多数的狐狸长年保持深色皮毛。
But dark coats leave them plainly visible against the snow.
然而深色外衣使它们在雪地里非常显眼。
So the Ptarmigan has plenty of warning.
因此，雷鸟有足够的预警。
With so little prey available, starvation is an ever present threat for the Icelandic Arctic fox.
猎物这么少，这对冰岛的北极狐来说挨饿就成了长期的威胁。
It often buries leftovers as emergency rations for leaner times.
它经常把吃剩的食物埋起来用作匮乏时期的应急口粮。
Finding its stash after a snow storm is a real challenge.
暴风雪过后找贮藏品可是实实在在的挑战。
