The North American Porcupine is a native resident of Pennsylvania, a large rodent known for its distinctive coat of sharp quills. This solitary mammal is often seen in forested areas across the Commonwealth. Porcupines are the second-largest rodent in North America, surpassed only by the beaver. Their range stretches from Alaska and Canada down into the northeastern United States, making their presence in Pennsylvania a natural occurrence.
The North American Porcupine in Pennsylvania
The North American Porcupine, scientifically named Erethizon dorsatum, is a stout, short-legged rodent with a pronounced arch to its back. Adults typically measure about 30 inches in length, including their short, club-shaped tail, and weigh between 9 and 15 pounds. Males can sometimes reach weights of up to 20 pounds, making them slightly larger than females.
Their coloring is generally a mixture of brownish-black or blackish fur, often sprinkled with yellow- or white-tipped guard hairs, giving them a grizzled appearance. These animals are highly arboreal, spending significant time in trees. They possess long, curved claws and rough, leathery foot soles that provide the necessary grip for climbing.
Where Porcupines Live in the State
Porcupines are not distributed uniformly across Pennsylvania but are concentrated in areas with extensive forest cover. Their population is strongest in the rugged mountains of northcentral Pennsylvania and the timbered land found in the northwest and northeast corners. They are also commonly found in the wooded sections of the state’s ridge-and-valley region.
The preferred habitat is a mix of hardwood and conifer woodlands, which provide food sources and suitable den sites. Fewer porcupines are encountered in the more developed southwestern and southeastern parts of the state. Dens are often situated in natural shelters like rock crevices, caves, hollow logs, or beneath brush piles. During the winter, they favor areas with hemlock and spruce trees for food and shelter.
Understanding Porcupine Behavior and Quills
Behavior and Diet
The North American Porcupine is primarily nocturnal, becoming most active to forage during the night. They are slow-moving animals on the ground, waddling along at a top speed of about two miles per hour. Despite their slow pace, they do not hibernate, remaining active throughout the winter.
As herbivores, their diet shifts seasonally, consisting of leaves, buds, and green plants in the warmer months. During the winter, they turn to chewing through the outer bark of trees to reach the nutrient-rich cambium layer underneath. They also possess a notable attraction to salt, which can lead them to chew on items like tool handles, plywood, or other exposed wood that has been treated with salt.
Defense Mechanism
The most recognizable feature of the porcupine is its defense mechanism: the quills, which are modified, hollow hairs. A common misconception is that the porcupine can “throw” its quills, but this is untrue; the quills are simply loosely attached. When threatened, the animal will tuck its head, erect its quills using specialized muscles, and lash out with its muscular, spiny tail.
Each quill has a needle-sharp tip covered with hundreds of microscopic, backward-facing barbs. These barbs cause the quill to easily embed upon contact and make removal difficult, as they are designed to migrate deeper into the flesh over time. For this reason, if a pet encounters a porcupine, the quills should be removed quickly by a professional to prevent them from working further into the body. Coexistence with porcupines is best achieved by securing any salt-treated materials, which removes one of the primary attractants for the animal.