Those Prickly Porcupines

by Chuck Loeffler

The Bent Tree Log - March 1994


Pity the persecuted porcupine.  He's been a native of North America for thousands of years and now is hunted, trapped, poisoned, and generally despised for making a living in the only way he knows how.  Although the porcupine is not the most common mammal in the Bent Tree area, it does occur here, and a few of our residents have encountered it - sometimes with unpleasant results.


The porcupine is the second largest member of the taxonomic order Rodentia (the rodents) in North America.  Only the beaver is larger.  Adult porcupines weigh an average of 20 to 25 pounds, although some large specimens may weigh 30 to 32 pounds.  It is a stout-bodied, short-legged animal, best known for its possession of sharp, modified hairs (quills), which it uses for protection against any creatures that may try to harm or kill it.  In addition to its quills, the porcupine also defends itself by omitting a strong, pungent odor to deter attackers - although it isn't nearly as potent as the odor of a skunk.


They are primarily nocturnal creatures, but may sometimes be seen during the day.  If they are in your area, you may see their tracks in the snow during the winter.  In deep snow they leave conspicuous drag marks, due to their short legs and low-slung bodies.  During Spring, Summer, and early Fall, they spend much of their time in trees, but during winter they will look for protection from the elements in dens made in hollow logs or natural rock crevices.


Porcupines mate (very carefully) in the fall, and give birth to a single young in early spring.  The newborn porcupines are black in color and weigh about a pound at birth.  The quills of the newborn porcupine are soft at birth (thank goodness, for the mother!), but harden quickly to provide protection for the young.  By early fall, the young porcupines are weaned and on their own, and their quills have developed a yellowish white color pattern, which functions as a visual deterrent to predators who may have had up-close-and-personal encounters with porcupines previously.


The porcupine's conflict with man is primarily due to its habit of gnawing and eating things which we don't want them to gnaw and eat - such as trees and wooden parts of buildings.  They feed almost exclusively on the bark, leaves, and buds of various trees, and have the habit of "girdling" branches.  "Girdling" is the removal of bark around the entire circumference of the branch or trunk of a tree, causing the portion of the tree above the girdled area to die, due to lack of nutrients, which must flow through the inner bark of the tree.  Usually, porcupine damage is limited to a few branches in the tops of trees, but occasionally an entire tree can be killed.  Although this does no serious or widespread damage to natural forests, it conflicts with people's desire to have perfectly shaped and aesthetically pleasing trees on their property.  The big, spiny rodents also have a particular liking, and need, for salt in their diet.  This also can lead to conflicts with man.  Many building materials (i.e. exterior plywood) have relatively high sodium content, and attract porcupines, who cause damage by gnawing on such materials.  Also, road salt applied to highways in winter can stick to car tires and other soft parts of cars and attract gnawing porcupines. (Another good reason to park your car in the garage at night, as per Bent Tree covenants!).


The other well-known hazard associated with porcupines, of course, is its ability to defend itself with sharp quills.  Usually, people need not worry about being "quilled", as the porcupine is a slow and shy animal, and will only use its quills against those foolish enough to get within a foot or two of the animal and put it on the defensive.  Dogs, however, tend not to recognize this hazard until they have had one or two personal encounters with a porcupine.  Unfortunately, this has resulted in trips to the veterinarian for a number of dog owners.  You can try to remove the quills from the dog yourself, but it's quite painful for the dog, and there have even been incidents of dogs biting their owners during this process, so give serious consideration to having your veterinarian do the job.


The quills of porcupines are really quite an amazing natural adaptation.  They are light-weight, but sturdy, and have tiny barbs on the ends, which is what makes them so difficult to extract.  In fact, these barbs will cause the quill to sink itself deeper and deeper into the body of the unfortunate animal who was stuck with them.  In some cases they may travel through part of the body to emerge several inches away and drop out.  Ironically, the quills are coated with an oily coating of fatty acids which actually act as antibiotics, thereby minimizing any possibility of infection from the quills.  The porcupine can not "shoot" or throw its quills, as some people believe.  They can, however, inflict the small quills on their tails in a victim with a very quick swat of the tail.


Nature has, unfortunately, made the porcupine a creature that does not mix well with people - especially in areas of higher human population.  It is classified as a "small game" species in Colorado, but landowners may legally kill them on their own property, without a small game license, at any time of the year to protect their property.  The porcupine is found throughout much of the United States, and most of Canada, and will, most likely, continue to thrive in the large, sparsely populated areas of North America, where it poses little threat to backyard trees and our curious pets.