While hiking around High Point State Park we came across a porcupine way up in a tree likely nibbling the branch tips.  After reading about this behavior, I learned that a study was done to x-ray the skulls of porcupines at a natural history museum and it turned out many had skull fractures from occasionally falling out of the trees in their efforts to get the tastiest tips.

Porcupine in Tree at High Point State Park, NJ