On a hike on the the Stone Valley Trail with my class I happened upon these pine branches scattered about in an unusual way. I learned that this was most likely due to a porcupine.The North American Porcupine (Erethizon dorsatum) is a herbivore that feeds on leaves, twigs, various fruits when available, and tree bark. They often climb to the top of pines and strip them of twigs and branches while trying to get to the sugary insides of the tree. They may live a range of 5-7 years (or in some cases more), and can have a population density of 1/mile^2 to 9/mile^2, approximately.