It's the only time of the year the wolves can hunt buffalo smaller than themselves.
这是一年当中狼群能捕食比牠们身材还小的野牛的唯一时间段。
There looks to be lots of calves in this herd. But to get to the calves, she has to somehow get past these intimidating adults.
这群野牛中看起来有很多小牛犊。但要接近这些小牛犊，牠还得搞定这些骠悍的成年野牛。
The female scout calls for some back-up.
母狼发出嚎叫声求援。

Storm and some of the pack's younger wolves quickly respond.
"风暴"和族群里的年富力强的狼们迅速回应。
You'd think with the calves around, the spring would make easier hunting for the wolves, but it's actually harder.
你们肯定在想到处是小牛犊，春天让狼群们捕食更容易了吧。事实上是更难了。
Buffalo mothers are fierce defenders of their calves and they're not encumbered by deep snow now.
母牛们顽强地捍卫自己的孩子，而且牠们的行动不再受厚积雪羁绊。
Again, the only chance for the wolves is to get the herd running and break up this defensive barrier.
所以，狼群们唯一的机会还是逼迫牛群们跑起来，破坏牠们的正面防御屏障。
The buffalo soon get strung out in a long line. This is what the wolves need.
野牛们很快惊慌地跑成一条直线，这正是狼群们所期待的。
Storm zeroes in on a lone calf. But with a burst of speed, it gets back to its mother.
"风暴"瞄上了一头落单的小牛犊，但牠的速度突然猛增，回到了牠妈妈身边。
Storm comes back for a second try. But even at full gallop, he can't get past the mother.
"暴风"回头再次追击，但即使牠全速追赶，也超不过母牛。
Wolves can run for hours, waiting for their chance.
狼群为了寻求机会能跑上几个小时。
But the buffalo have incredible endurance, too, even the calves.
但野牛也有这不可思议的耐力，即便是小牛犊。
I've seen these chases go on for 20 miles.
我见过类似的追逐有二十多英里远。
But an opportunity for the wolves lies ahead.
但狼群们的机会即将到来。