Back in Iceland, in their beach side den, ten fox cubs still suckle on their exhausted mother.
冰岛海岸边的狐狸窝里，十只小狐狸仍在吮吸妈妈的乳汁，而妈妈已精疲力竭。
It's been nearly a week since her mate went missing.
她的伴侣失踪将近一周了，
She's having to look after herself and her family alone.
不得不独自照顾自己和孩子们。
Desperate to replenish her energy in order to provide enough milk for her cubs,
它急需补充体力才能让孩子们有足够的奶水，
She's forced to leave her litter and venture out.
它被迫离开幼崽，冒险出去。
Her passage to the landscape over the next few days is marked by tufts of her white winter fur.
这一路上，在几天之内都会留下一簇簇它那白色的冬季软毛。
The Arctic fox has the most insulating coat of all mammals.
北极狐的皮毛是哺乳动物中隔热性最好的。
It's essential to endure winter temperatures as low as minus 50 degrees Celsius.
那是帮助它们忍受冬季摄氏零下五十度低温的必需品。
But with temperatures rising, the coat becomes a nuisance.
但是现在气温正在回升，厚厚的外衣就成了累赘。
But darker summer coat helps keep her cool and blend in with the surroundings.
而颜色较深的夏装不仅能使其凉爽，还能和周围的环境相融。
But today she can't afford to worry about comfort or stealth.
但是今天，它顾不上是否舒服，也顾不上能不能隐秘。
It's food she's after.
它关心的是寻找食物。
In Iceland, seabirds are a staple of the fox's diet, but there are very few on the vixen's territory.
在冰岛，狐狸的主要食物是海鸟，可是这只雌狐的地盘上却没有多少。
On the beach, the spring tide has been kind, delivering the meal she desperately needs.
海滩上，春季的潮水很慷慨，带来了它急需的食物。
The fish will keep her and her cubs alive.
这块鱼肉能够让它和幼崽们活命。
But her feast will have to be cut short.
然而它的盛宴被迫打断。
She needs to get back to her family, there's an intruder prowling her territory.
它必须回到孩子们身边，有个入侵者正在它的领地内窥探。
