Perhaps it would be well if we could think of the grizzly as being largely vegetarian. He digs up roots; feeds on weeds, tender shoots of shrubbery, fungi, mushrooms, berries, seeds, rose-hips, pine-nuts, and acorns; and also eats bark like a rabbit and grass like a grass-eater.
The aspens were in bloom, laden with swollen buds and juicy catkins. Many birds were feasting on the catkins; and, looking over into a near-by aspen thicket, I saw a grizzly on a ledge also feeding eagerly. Reaching for a limb, first with one fore paw and then the other, he bit off a few inches and ate twigs, bark, and bloom. Occasionally he seized the top of an aspen with both paws, bent it down, and bit it off. It was similar to the fashion followed in eating wild plums and choke-cherries. A bear will reach up and pull down the top of a plum tree, and, biting it off, eat the small limbs, the bark, the leaves, and the fruit. A grizzly browsing in a wild raspberry-patch will bite off the tops of the vines together with the berries, the leaves, and the thorns. Sometimes the twigs and terminal buds of the pine, the fir, and the spruce are eaten.
One day I saw a grizzly approaching in a manner which indicated that he knew exactly where he was going. On arriving at an alder clump by the brook he at once began tearing off the bark and eating it. On another occasion I watched a bear strip nearly all the bark within reach from a young balsam fir. I have often seen places where bears had bitten and torn chunks of bark from aspens and cottonwoods. Though they also tear the bark from pine and spruce trees, I do not believe that this is eaten as frequently as the bark of the broad-leaved trees.
During the first few weeks after coming out of the winter den much of the grizzly's food is likely to be of the salad order--juicy young plant stalks, watery shoots, tender bark, young grasses, buds, and leaves. In late autumn, just before hibernating, his last courses are mostly roots and nuts.
However, the normal grizzly is an omnivorous feeder, refusing only human flesh. He will eat anything that is edible--meat (fresh, stale, or carrion), wasps, yellow-jackets, grasshoppers, ants and their eggs, bugs, and grubs. Of course he eats honey and the bees. He also captures snakes, and many a rat and rabbit. He is a destroyer of many pests that afflict man, and in the realm of economic biology he should be rated high. I doubt if a dozen cats, hawks, or owls annually catch as many mice as the average grizzly.