The North American porcupine, Erethizon dorsatum, is a large rodent that occurs in Alaska and Canada, as well as in much of the northern and western contiguous United States. The species is common in Utah, where it prefers coniferous forest and mixed forest areas, although it may also be found in riparian zones, deserts, and shrubland habitats. Porcupine dens may be found in hollow trees, hollow logs, and small caves. The porcupine is active throughout the year and is mainly nocturnal, but is often visible during the day.
Breeding occurs in the fall, and females may give birth to one young in late spring. The porcupine eats bark, roots, berries, buds, fruits, leaves, and other plant material. The needles and bark of coniferous trees are often consumed during the winter. Porcupines are covered in sharp spines, or quills, that are used for protection from predators. Quills usually lay flat against the body, but may be raised when danger is near. Quills are loosely attached to the body and may detach from the porcupine and lodge into a predator if touched; porcupines cannot shoot their quills.