North American Porcupine

Porcupine on a stack of wood by Mary Meagher-NPS (public domain)

North American Porcupines are large, solitary rodents common in New England, but less common and rarely seen in Connecticut. They are stocky with an arched back and short legs. Long hairs on the front of their body are black or dark brown. In the west this hair can be yellowish. Quills of different sizes cover most of the porcupine's body except for the face and part of the belly. Quills and some long hairs have white tips. The soles of a porcupine's feet have no fur and have a textured surface for better gripping. The tail is thick and muscular and 6 to 12 inches long. Porcupines weigh 8 to 30 lbs.

Porcupines range through New England, much of the western half of the US, most of Canada, and Alaska. They live in forests. They are active year-round and are mostly nocturnal, but may be seen out in daylight. A porcupine may rest in the top of a tree during the day. They will den in tree cavities, holes among rocks, in underground burrows, and under logs. Areas with Eastern Hemlocks are often prefered for dens. In very cold weather a porcupine spends alot of time in or near its den, and Hemlock needles are a favorite wintertime food.

Porcupines are herbivores. Typical diet in the wild consists of tree leaves, twigs, buds, seeds, nuts, fungus and green plants. Evergreen needles and bark are eaten in the winter. A porcupine's usual diet does not supply much salt so they tend to crave it. They will obtain salt from aquatic plants or from road salt. Porcupines have made pests of themselves by gnawing away hand-tool handles that have absorbed salty human sweat.

Porcupines mate in October to November and produce a spring litter in May or June. A receptive female will lower her quills and lift her tail up over her back. This allows the male to mate with her without implaing himself.

Porcupines are largely arboreal and are adapted to climbing trees. The soles of their feet are textured for gripping and they have large claws for climbing. Their tail is also used for climbing. It has stiff bristles underneath which point backwards. When pressed against a tree trunk these bristles prevent slipping. A porcupine lifts and lowers its tail when climbing down a trunk, using it to feel its way down. On the ground porcupines waddle along slowly and somewhat awkwardly. Their eyesight is very poor, they are quite nearsighted.

Porcupines are not aggressive but they are very well defended. Up to 30,000 modified hairs called quills cover most of their their body and tail. Quills are sharp and range from 1 to 3 inches in length and have tiny, microscopic barbs on their tips. Porcupines cannot shoot or throw their quills from a distance. The quills come out easily when contacted. The tail of a porcupine has a white-bordered dark stripe down the center believed to be a warning pattern, like the skunk's black and white striped pattern warns of its defenses. If threatened a porcupine will chatter its teeth repeatedly and can produce a strong unpleasant odor. The quills are connected to voluntary muscles and a porcupine can raise them so they bristle out. It may thrash its tail back and forth. If the animal still chooses to attack, the porcupine's quills are only loosely connected and will embed themselves in its attacker upon contact. This is usually the face and head if the attacking animal is trying to bite. The barbs on the quills will cause the quills to gradually work their way deeper into an animal's flesh. The shorter quills can go the deepest and are the most dangerous. If they work in deeply enough they can pierce something vital. Most predators quickly learn to avoid porcupines. Fishers can successfully prey on porcupines by flipping them over and attacking their un-quilled bellies or un-quilled heads. If your dog has tangled with a porcupine, make sure all the quills are removed as soon as possible. A vet visit is probably a good idea to ensure complete removal and prevent infection. At least it will probably only ever happen once per dog.

Neat Fact

Love takes many forms. An amorous male porcupine will approach a female standing on his hind legs and tail while making whines and grunts. He will then soak her down with a high-powered spray of urine. You'd think this procedure would have ensured no baby porcupines were ever born, but a receptive female will respond favorably to this treatment. (Even if she is not receptive, she will simply waddle away unconcerned). Apparently charmed by her shower, a receptive female will also stand on her hind legs and the pair will embrace while grunting and whining. The female often gets soaked a second time. In order to mate the female will present her hind end, relax her quills and raise her tail to allow the male safe access.