The grizzly and the wolf -- they couldn't be more different...

What happens when two great predators come face to face in Yellowstone? The bear is a loner, ranging far and wide in search of a rich variety of resources. The wolf hunts to survive and finds its strength in speed and teamwork. Their strategies have taken them to the very top of the Yellowstone hierarchy, and it's no simple matter when they meet face to face...NATURE...7pm