Grizzlies are always hungry. It’s no wonder, because of a five month hibernation fast, they must go into the den at least 150 pounds over the weight from which they emerge. This large, aggressive omnivore (meat and vegetation eater) is in reality a very poor predator. Meat is preferred, but not often an option. As a result, the animal consumes a wide variety of food stuffs.
Their favorite food is ground squirrels, which they vigorously dig for. Other meat sources may include fish, newborn mammals, and carrion from winter kill. However, 70% of their diet is grass. It needs to be moist and at least 4 inches long because they graze with a sideways motion of the head. It’s interesting to watch them grazing on a hillside like cattle. Other foods are insects, buds, berries, nuts, and roots.
That hump between the shoulders is a massive muscle for digging, which they are masters at. They require a massive 24,000 calories a day, and their digestive tract is 80 feet long (10 feet for each foot of body length – humans have 4 feet for every foot of height). This great length of gut enables the digestion of a truly great variety of food stuffs. The bear is most aggressive when guarding a carcass, or when a sow is guarding her cubs. The bear is also very fast. Grizzlies can cover 50 yards in 3 seconds. My wife and I watched one ambling along, when suddenly the bear became alert and was off. It was amazing how fast that beast covered the ground and was gone!
Once, in a Canadian campground, I was sitting and reading to my wife. Our backs were toward the woods. A man came up the trail, on his way to the restroom. He asked if we had enjoyed our visitor. Evidently, a Grizzly had come out of the woods and sat behind us, unbeknown to us. It then, when seeing the man approaching, had returned into the trees.