They may be adorable from a distance, but porcupines possess a formidable defense system unique to North American mammals. When threatened, these members of the rodent family—whose name literally means “spiny pig” in Latin—extend their quills and swing their tails toward attackers, often depositing dozens of barbed quills into hapless victims.
Porcupines are primarily nocturnal, so conflicts with humans are rare; a direct hit to the wandering family pet, however, often requires a late-night trip to the veterinarian. If you’ve ever let your dog or cat roam at night, you may be all too familiar with how effective the porcupine’s defenses truly are: the quills penetrate flesh easily but are not easily removed.
Generally, however, these slow-motion herbivores are benign, avoiding confrontation in their homes—mixed and coniferous forests throughout the western United States. In Utah, they’re common in virtually all of the state’s mountain ranges.
In the Park City area, they may be a little too common for some multimillion-dollar homeowners who meticulously landscape with elegant fir, spruce, and pine trees. Such pricey, nursery-bred trees are like buffet stations for porcupines, who home in on them as a primary food source during Park City’s long, cold winters. By far their favorite cold-weather fare is the soft underbark of conifers called the cambium layer, but in order to get to the delicacy, the toothy critters must first chew off the outer bark, leaving a tree scarred and dying.
Porcupines are actually most active in the summer, when they’re more dispersed and far less visible, feasting unseen on the branches, leaves, seeds, and berries widely available across the mixed-forest floor. But in winter, when the leaves of many trees have fallen, they’re easily spotted and can sometimes be seen in trees along the edges of south-facing ski runs, munching away among upper branches and posing for pictures.
David Clark, a manager at Park City Nursery, says he doesn’t know of any tree, plant, or shrub that’s naturally resistant to porcupines. “They’re not overly active in the winter, but when they do come out, they’re going to eat something,” he says. Clark outlines a couple of options for protecting high-value trees: wrapping the trunks with fencing or chicken wire up to about four feet or using Plantskydd, a product developed in Sweden, which the makers claim repels deer, rabbits, moose, squirrels, beavers, and, yes, porcupines.
Porcupines are listed as protected by the Utah Division of Wildlife Resources, so it’s hands (and paws) off if you find one feasting in your backyard. This is especially true for Fido, who will quickly find himself with a nose full of quills if he ventures too close.