Coyote hunting Bighorns

It is rare to see a chase or hunting sequence in Yellowstone. Most of the time the animals are eating, eating, or just plain eating. A fellow visitor told me a coyote was hunting these bighorns but I said "No, they are just in the rut." He had witnessed a coyote chase one of the sheep over the cliff a few years ago.  Once again humbled in Yellowstone.