PORCUPINESThe porcupine is a rodent known for its coat of sharp spines, or quills that defend it from predators. The porcupine is the third largest rodent, after the capybara and the mara.
Identification
Porcupines (Erethizon dorsatum), sometimes called “porkies” or “quill pigs,” are heavy-bodied, short-legged, slow, and awkward rodents, with a waddling gait. Adults are typically 25 to 30 inches (64 to 76 cm) long and weigh 10 to 30 pounds (4.5 to 13.5 kg). They rely on their sharp, barbed quills (up to 30,000 per individual) for defense.
Range and Habitat
The porcupine is a common resident of the coniferous forests of western and northern North America. It wanders widely and is found from cottonwood stands along prairie river bottoms and deserts to alpine tundra.
Food Habits
Porcupines eat herbaceous plants, inner tree bark, twigs, and leaves, with an apparent preference for ponderosa pine, aspen, willow, and cottonwood. Trees with thin, smooth bark are preferred over those with thick, rough bark. Porcupine feeding is frequently evident and has considerable impact on the cottonwood stands of western river bottoms.
General Biology, Reproduction, and Behavior
Porcupines breed in autumn, and after a 7-month gestation period usually produce 1 offspring in spring. Although the young are capable of eating vegetation within a week after birth, they generally stay with the female through the summer. Juvenile survival rates are high.
Predators of porcupines include coyotes, bobcats, mountain lions, black bears, fishers, martens, great horned owls, and others. Coyote scats (feces) containing large numbers of quills are not unusual. How the quills are maneuvered through the coyote’s gastrointestinal tract is a mystery.
Porcupines are active year-round and are primarily nocturnal, often resting in trees during the day. They favor caves, rock slides, and thick timber downfalls for shelter.
Economics of Damage and Control
Economic losses can be considerable from porcupines feeding on forest plantings, ornamentals, and orchards as well as on leather and other human implements. Porcupines generally are tolerated except when commercial timber, high-value ornamental plantings, orchards, or nursery plants are damaged by girdling, basal gnawing, or branch clipping. On occasion, porcupines thin dense, crowded forest stands. Often tree diameter growth is reduced. Their preference for mistletoe as a food is an asset.
The porcupine is acclaimed as a beautiful creature of nature. It is an interesting animal that has an important place in the environment. It is edible and has been used by humans as an emergency food. The quills are used for decorations, especially by Native Americans. The hair, currently used for fly-fishing lures, commands many dollars per ounce. Porcupines are not wary and can be readily observed and photographed by nature lovers. Porcupines may need to be controlled but should not be totally eradicated.
Damage Prevention and Control Methods
Exclusion
Fences (small areas). Tree trunk guards.
Cultural Methods
Encourage closed-canopy forest stands.
Repellants
None are registered. Some wood preservatives may incidentally repel porcupines.
Toxicants
None are registered.
Fumigants
None are registered.
Trapping
Steel leghold trap (No. 2 or 3). Body-gripping (Conibear®) trap (No. 220 or 330). Box trap.
Shooting
Day shooting and spotlighting are effective where legal.
Other Methods
Encourage natural predators.
ACKNOWLEDGEMENTS
The above information was adapted from PREVENTION AND CONTROL OF WILDLIFE DAMAGE with permission of the editors, Scott E. Hygnstrom, Robert M. Timm, and Gary E. Larson (Cooperative Extension Division, Institute of Agriculture and Natural Resources University of Nebraska-Lincoln, United States Department of Agriculture Animal and Plant Health Inspection Service, Animal Damage Control, Great Plains Agricultural Council Wildlife Committee).
