If you've ever read a wilderness survival book worth it's salt, you've read about the nutritional qualities of bark. I guess I shouldn't knock it until I try it, but I would resort to eating bugs before bark. Somehow I can't help but think eating bark would be like forcing down a huge bowl of dry, shredded wheat... except more bland.
A number of animals at Pinkham Notch disagree with my bark-eating assessment, however. In fact, during the winter months bark is a major food source for moose, porcupine, beavers, and snowshoe hare. Lack of green, leafy vegetation forces these mammals to seek alternative food sources.
Yesterday, while snowshoeing, our group came across a tree with its bark recently scraped off by a moose. Moose use the shovel-shaped incisors on their lower jaw to shave bark off the tree, leaving long, orangish tooth marks on the trunk. They usually target smooth, pole-sized trees, like young red and striped maple or mountain ash. The scrapes will always run up the tree, as moose only have incisors on their lower jaw.
In addition to eating bark, moose will also dine on buds during the winter months. Watch for branches with ends that have been roughly torn off. Sometimes, as in the photo, moose will unintentionally break the branches while ripping off buds.