As the ice caps melted, temperatures began to rise.
随着冰盖的融化，气温开始升高。
Plant life that had adapted to colder climates died on a large scale.
已经适应更寒冷气候的植物大批死去。
The result was a mass migration of the herbivores that consumed them.
其结果就是以它们为食的植食动物大规模迁徙。

With fewer plant eaters to hunt, predators were also pushed to the edge.
能够猎杀的植食动物变少了，掠食者们也被推向极限。
Usually, even the toughest predators will stick to their own territory to avoid risky clashes with other meat eaters.
一般，即使最厉害的掠食者也会留在自己的领地，以避免与其它肉食者冲突的危险。
But when the food gets scarce, caution is abandoned.
不过当食物缺乏之时，就顾不上小心了。
At the end of the Ice Age, the huge lion and the gigantic bear were pushed to desperate measures.
在冰期末期，巨大狮子和熊被逼得孤注一掷。
Well, I think the first thing that we should realize is that we're looking at the epitome in these two animals.
我认为我们首先要明白的是，我们看到的是这两种动物的缩影。
The American lion is arguably the largest and most powerful feline that ever lived.
美洲拟狮有可能是有史以来最大最有力的猫科动物。
And the short-faced bear is certainly the largest, most powerful bear that we have any evidence for.
而短面熊毫无疑问是我们所知的熊类中最大、最有力的一种。
In fact, the short-faced bear is probably the largest and most powerful mammalian carnivore that we have.
其实，短面熊有可能是有史以来最大、最有力的哺乳类食肉动物。
And as such, even though this would be one heckish powerful lion, this bear would be so much more powerful that I really think it could skin the lion.
因此，尽管这是一头拟狮本身也很强大，这种熊要比它力量大得多我认为它可以剥了狮子的皮。
The lion was more intelligent than a house cat.
拟狮要比家猫更加聪明。
It knew how to uses its speed, to outmaneuver its prey.
它知道如何利用速度，以以谋略制胜其猎物。
With lightning-fast jabs and assaults, it moved with power and purpose.
它的猛击突袭快如闪电，移动有力，目标清晰。
The short-faced bear was not as strategically minded - its plan of attack involved a headlong rush.
短面熊没那么有战略头脑，它的攻击方案就是横冲直撞。
The bear is actually pretty fast.It's got those elongated legs because it's designed to run over a long distance.
这种熊的速度其实相当快。它的腿很长构造很适合长距离奔跑。
So speed wise, it may not have been as fast as the lion, but it certainly could run much greater distances than the lion.
所以从速度来说，它也许没有狮子那么快，但却肯定能比狮子跑更远的距离。
The lion on the other hand is a cat, and cats are very quick, very agile, very fast animals.
从另一方面来说，狮子是猫科动物，猫科动物非常迅速、异常敏捷