On the open plateau, right in the middle of this frozen volcano, is an animal that has lived here since the last ice age. Bison are exposed to the worst of the Yellowstone winter. But, they are built for it. Their thick coat is such good insulation that they only need a tiny amount of energy to keep warm. So, they slow their metabolism right down and concentrate on feeding. With massive neck muscles, they sweep their heads down through the snow to get to the grass beneath. But, the grass has long ago put its summer goodness down into its roots and now has about the same nutritional value as cardboard.

They will need to do all they can to save energy if they are to ward off starvation until spring returns. As the winter strengthens its grip, elk move into more sheltered valleys at the edge of Yellowstone. They don't have the bison's ability to move deep snow. But, this brings them into the territory of the Druid pack. As the grazers are beginning to weaken, life for the wolves is getting easier. They are now successfully hunting about twice a week. They even have the energy to play. But, their play has a purpose. It fine-tunes their hunting skills and helps bond the all-important pack structure. Though there are 16 of them, they can

only hunt an animal as large as an elk if they hunt as one. The strength of the pack is what will get them through the winter. Bald eagles spot carcasses from miles away. But, there is strong competition for a kill like this. A coyote. He has been shadowing the wolves and moves in now they have gone.