Common Porcupine

Also known as
Porky, hedgehog, quillpig, porc epic, stachelschwein, pricklepig, quiller.
What is the scientific name?
Erethizon dorsatum
Where are they located? How many subspecies are there?
Porcupines are found mainly in the western half of the United States and Canada. In the east they occur in the New England states, New York, Pennsylvania, Michigan and Wisconsin. There are seven subspecies: E.d. bruneri, E.d. couesi, E.d. dorsatum, E.d. myops, E.d. nigrescens, and E.d. picinum. E.d. epixanthium occurs in most of the northwest and California (Woods 1973).
Where do they live?
Usually in forested, brushy areas but they also may be found in deserts, rangelands and riparian zones (Nowak 1991).
What do they look like?
Usually a brownish color, but western porcupines (E.d. epixanthium) are yellowish in color. They often walk pigeon toed and have no distinguishable neck. Quills cover most of the body, except the nose and stomach, and the quill tips are black or very dark brown. Quills along the tail are thickest and are the most likely to be used in defense. The Porcupine has over 30,000 quills on its body (Woods 1973).
How big are they?
Males and females are similar in size. Porcupines are between 25 and 41 inches long, tail included, (Hall 1981) and weigh between 8 and 14 pounds (Dodge 1982).
How long do they live?
Uncertain, but probably five to seven years in the wild (Dodge 1982). The oldest wild porcupine ever recorded was estimated to be 18 years old (Earle and Kramm 1980). Captive porcupines have also lived to be more than 10 years old (Brander 1971).
What do they eat?
Primarily the inner bark of trees and evergreen needles, especially conifers such as Douglas Fir and Ponderosa Pine, and hardwoods such as oaks and birches. They also eat aquatic plants, berries, seeds, flowers, nuts, and grasses (Woods 1973; Dodge 1982).
How do they reproduce?
Very carefully.

Interesting notes: Porcupines do not "throw" their quills as many people believe. They are unaggressive and reportedly never attack other animals. Their quills are used only for defense (Nowak 1991). The hollow quills are loosely attached to the porcupine's body and a predator must come into physical contact with it to sustain injury. When threatened the porcupine erects its quills, taking on the look of a massive pincushion. If a predator attacks, the porcupine flicks its tail back and forth hammering its quills into its enemy. The heavily muscled tail can drive the quills over one-half inch into a predator's flesh. The quills have tiny backward-facing barbs that, once embedded, cause the quills to work their way deeper into the skin at the rate of up to one-third of an inch per hour. These barbs also expand when imbedded in tissue making their removal extremely difficult and painful (Nowak 1991; Maser 1981; Dodge 1981).

Porcupines have caused the death of many unwary animals such as owls, eagles, dogs, cattle, horses, and even people (Lano 1922; Dodge 1981). Regardless of their pointed defense, porcupines find themselves victims of predators that have learned to roll them on their back and expose their unquilled soft belly. Cougars, bobcats, coyotes and especially fishers have all been competent at attacking and killing porcupines without receiving injury (Maser 1981). Because the porcupine's habit of eating trees has the unfortunate effect of damaging the tree, fishers have actually been introduced to certain areas in an attempt to control the porcupine populations (Nowak 1991). Porcupines were once so highly disregarded for their tree damaging behavior that Central Oregon exhibited highway signs that said "Please kill all porcupines" (Maser 1981).

Salt is often sought after by porcupines and they will gnaw on antlers and bones when found (Nowak 1991). They have also been known, for reasons not completely understood, to gnaw on vehicular hydraulic lines, tires, steering wheels, seat coverings, shift knobs, electrical wiring, aluminum canoe seats, canoe paddles, and axe handles (Dodge 1981).

Last updated April 16, 2006
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Copyright 2006, by Jim Rible