Do Porcupine Eat Bark?

Do Porcupine Eat Bark? Do Porcupine eat bark? Porcupines primarily feed in the tree canopy throughout the winter by chewing evergreen needles, bark, twigs, and buds off trees. In the interior West, including Utah, cottonwoods, willows, pines, Douglas-firs, spruces, and true firs are preferred by porcupines, especially for their bark. Does a porcupine eat wood?