Body length: 18 - 22"
Diet: Inner bark of trees, buds, cacti
Many people are surprised to hear that porcupines live in the desert. In fact, although usually found at higher elevations in Arizona, this wood-gnawing rodent of the forest is an occasional visitor here as well. Desert porcupines feed on the bark of mesquite and the fruit of prickly pear cactus. Porcupines are best known for their quills, which are actually modified hairs. Quills are an effective defense against predators such as dogs, although mountain lions can learn to roll them over and kill them by slashing at their unprotected underside. Porcupines cannot throw their spines, but they come out readily when the animal is touched.
Porcupines are indeed unusual rodents, belonging to a separate branch of the rodent family that occurs mainly in South America.