This is a video of a riveting encounter with a pack of wolves in Yellowstone last winter. It was fascinating to watch the pack work as a group to bring down the bull elk. Although one of the bull's antlers was broken, he still kicked and it was a wonder that none of the wolves was injured.

This is a classic example of the wolves taking the weakest, as the other healthy bull elk was ignored, and the wolves targeted the elk with the broken antler.

http://www.youtube.com/watch?v=Wi0J3CFqiXo