Mass: 3.5 to 7 kg
Length: to 40 in. (100 cm)
Biomes: tundra, taiga, temperate forest & rainforest, temperate grassland, desert
Status: no special status.
Range:The common porcupine is found in boreal North America from Alaska to Labrador and southward to northern Mexico. Erethizon is also found in the Lake States and New England. In the north-central region, it is found only in Michigan, Wisconsin, and Minnesota.
Coloration of common porcupines is usually dark brown. The dorsal region of the porcupine is covered with thick, sharp, barbed quills, which are distributed among stiff guard hairs and wooly underfur. The number of quills on each porcupine may exceed 30,000. The quills are used for defense purposes. Each one of the modified hairs is tipped with microscopic barbs that cause the quill to be continually driven into the muscle of predators. Common porcupines have robust bodies with small heads, moderately small ears, short legs, and a short thick tail.
When approached by predators, the porcupine faces away from its enemy, raises its spines in a threatening gesture, and rapidly lashes out with its barbed tail. The quills of the porcupine are not thrown or shot but easily detached after contact with a predator's flesh. Porcupines have poor vision but good senses of hearing and smell. The voice of the common porcupine has been described as a combination of moans, whines, grunts, squeeks, snorts, and shrieks.
The animal's feet are heavy with naked soles. The front feet have four toes while the hind feet have five toes. Each toe has a strong curved claw.