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Poor Old Porcupine

30,000 quills – AND he falls out of trees. Ouch!

By Nancy Cain
Published: October 1, 2004
Photo by Hawk Creek Wildlife Center
You’re walking along in the woods, all is quiet, and you come upon a clicking critter resembling a waddling pincushion. You’ve stumbled into a rare encounter with one of the most misunderstood of North American mammals – the porcupine.
Stop and watch it for a while – it is not shy or dangerous unless threatened. You probably wouldn’t be shy either if you were covered with 30,000 potentially lethal weapons.
The name “porcupine” is derived from Latin for “pig” and “spine,” but it’s not even related to pigs. Porcupines are rodents – big ones. In North America, they are typically 15-20 pounds and second in size among rodents, with the beaver claiming top honors.
Porcupines are active year-round and typically live in earth dens, rock caves and hollow logs. They are vegetarians who forage on all types of vegetation in the spring and summer. And porcupines are messy eaters. In fact, if you spot an area in the winter littered with “niptwigs” – the short ends of conifer tree branches that have been trimmed of buds and needles – that’s a sure sign of their presence.
Why porcupines love cabins. As vegetarians, porcupines appear to crave sodium, probably because their bodies need it to balance blood cell potassium levels. It is their passion for salt that often brings them into contact with cabin-owning humans, who are astonished to find them chewing on plywood (the glue is salty), canoe paddles, tools that have absorbed human perspiration, and the wires on the salty undersides of automobiles in late winter.
Porcupines are known most for their unusual armor, the quills that adorn their bodies. These quills are actually hairs modified into spines with many microscopic barbs on the tips. The inside of each quill is filled with a spongy matrix. When a quill enters the flesh of an attacker, the sponge-like interior of the quill fills with blood, causing the quill to expand and to embed deeper and deeper into the flesh.
Contrary to common perception, porcupines do not have the ability to shoot their quills like miniature spears at enemies. Rather, the quills are loosely attached to muscles. As the porcupine lashes its muscular tail against an attacker, dozens of quills are hammered into the assailant and detached. The quills are not meant to be a weapon; rather they’re a defense mechanism designed to educate unsuspecting predators. 
Photo by Hawk Creek Wildlife Center
More than just quills. Look-ing at those quills, it seems like overkill that porcupines have two other warning systems. Like skunks, porcupines have a contrasting black and white warning pattern, with a black stripe running up the middle of the back and white on the head. Porcupines also have the ability to produce a strong, pungent odor on demand. These two warning systems, combined with an initial quill strike, ensure that potential predators get the point.
Interestingly enough, the animal most often stuck with quills is the porcupine itself. This usually happens during the course of social interaction or when falling out of a tree (35 percent of captured porcupines have fractured skulls). Because the animal can quill itself, there is a mild antibiotic located on the tip of each quill.
But that doesn’t make cabin and cottage owners any more comfortable about the thought of our dogs tangling with one! Embedded quills sink into flesh at a rate of up to one-third of an inch per hour and often require medical attention for removal. If you happen to be way out in the woods and your dog has been quilled, the best thing to do is to cut off (or bite, if you have to) the end of each quill, leaving plenty of the quill so you can grip it. This releases air pressure in the quills, deflating the spongy interior, and allows you to remove the quills or at least prevent them from embedding as quickly.
No fear. Porcupines have few natural enemies, with the exception of the fisher, which is extremely quick and kills by repeated facial attacks. Porcupines often climb trees to escape, but the fisher has an ability – unique among predators – to hinge its back legs, allowing it to hunt while coming headfirst down a tree. In contrast, the porcupine must descend back end first. A fisher that has climbed higher than a porcupine is at a huge advantage, since it can confront the porcupine head-on without worrying about the porcupine’s muscular, quill-covered tail.
You don’t often get to see a live porcupine. If you do, realize it’s a one-of-a-kind critter who has earned the respect of all by making its point: “I may waddle and look like I’m having a bad hair day, but don’t mess with me!”

With a doctorate in animal behavior, Nancy Cain particularly likes writing about prickly topics.
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