Just watched this same clip on animal planet. When I guided we had a grizzly that would slaughter elk calves every spring. I remember one time riding into a meadow and seeing this Hereford bull moving. It was already dead but the grizzly was up inside the body cavity. It was an eire feeling when that bear was around. Bears are hard on elk calves.
In the spring around here the elk calve in the valley bottem and the Grizzlies move in to.They routinely prey on elk and moose calves, sometimes we can see this from home.