The calves are born well before the spring melt,
牛犊出生在春天冰盖融化之前,
giving them a head start when summer finally arrives.
这样可以顺利地迎接夏天的到来。
It must get to grips with its new ice world, benign one minute, life-threatening the next.
它们必须适应这个冰雪世界,但天气喜怒无常。
Even in spring, winds chill to the bone.
即使是春天,仍然寒风彻骨。
The calf must stay close to its mother to avoid getting lost in the sudden blizzard.
小牛必须紧跟着母亲才能避免在突如其来的暴风雪中迷路。
![BBC纪录片 地球脉动 BBC纪录片 地球脉动](http://pic.kekenet.com/2017/1127/22551511763668.png)
Arctic wolves! In the whiteout, the threat is almost impossible to detect,
北极狼!在白茫茫的天气中,有危险也几乎不可能察觉到,
but the musk oxen instinctively retreat to higher ground.
但是麝牛本能地向高地撤退。
Forming a defensive ring around their calves, the adults present a barricade that few hunters could breach.
成牛围成圈以保护它们的小牛,一般的猎食动物很难突破这层封锁。
But the wolves need not risk injury today.
但是今天的这头狼不需要冒受伤的危险硬闯。
A calf has been left behind in the panic.
它们在慌乱之中留下一头小牛。