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“A North American porcupine may carry roughly 30,000 quills.”
The North American porcupine is a large nocturnal forest rodent defended by thousands of barbed quills. It climbs trees to feed on bark, needles, leaves, and buds, and is listed as Least Concern across Canada, Alaska, and much of the northern United States.
Erethizon dorsatumRodentiaErethizontidae
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
The North American porcupine (Erethizon dorsatum) is the continent’s second-largest rodent after the beaver and the only porcupine native north of Mexico. Slow on the ground but surprisingly sure-footed in the canopy, it is a nocturnal forest herbivore defended by tens of thousands of barbed quills. From boreal spruce woods in Canada and Alaska to mixed hardwood stands in New England and mountain forests of the West, this solitary climber shapes trees by stripping bark and cambium — and remains one of North America’s most unmistakable mammals.
The porcupine belongs to kingdom Animalia, phylum Chordata, class Mammalia, and order Rodentia. It is the sole living species in the genus Erethizon and a member of family Erethizontidae, the New World porcupines. That family is distinct from Old World porcupines (Hystricidae), such as African or Asian Hystrix species, and from South American prehensile-tailed porcupines in the genus Coendou.
New World porcupines evolved in the Americas as arboreal, plant-eating rodents. Erethizon dorsatum specialized for cooler northern forests: a stocky body, dense underfur beneath the quills, strong claws for climbing, and a long gut able to ferment tough woody tissue. Quills are modified hairs — an independent defense strategy that differs from the bony armor of an armadillo or the clever foraging tools of a raccoon, both of which may share parts of the same landscape.
Adults typically measure 24 to 36 inches (60–90 cm) in body length, with a short, thick tail of roughly 6 to 12 inches (15–30 cm). Weight usually falls between 10 and 30 pounds (4.5–14 kg); large males can exceed that. The silhouette is chunky, with a small head, blunt snout, and short legs.
The coat is a mix of soft underfur, long guard hairs, and roughly 30,000 quills concentrated on the back, sides, and tail. Each quill has microscopic reverse barbs at the tip, so it tends to work deeper into tissue once lodged. Contrary to folklore, porcupines cannot shoot quills. Quills detach easily when an attacker presses into them; the animal may also thrash its quilled tail. Front claws are long and curved for gripping bark, and the soles of the feet are rough, aiding traction on branches.
Vision is modest, but hearing and smell are useful for night travel. The skull and continuously growing rodent incisors allow porcupines to gnaw bark, wood, antlers, and bones — useful both for food and for mineral intake.
North American porcupines occupy a broad forest belt across Alaska, most of Canada, New England, the Great Lakes region, the Rockies, and parts of the western United States; isolated populations also occur farther south in mountain or woodland habitats. Preferred cover includes coniferous, deciduous, and mixed forest with climbing structure and winter browse.
By day they may rest in trees, rock dens, hollow logs, or thick brush. At night they move along familiar routes on the ground and climb to feed. Winter use often centers on stands of preferred browse trees, where bark-stripping leaves distinctive feeding scars. They swim when necessary and endure cold with insulating fur beneath the quill layer.
Porcupines are dedicated herbivores. Seasonal diet shifts are stark. In summer they eat grasses, herbs, leaves, buds, and fruits. In winter, when green plants are scarce, they rely on evergreen needles, twigs, inner bark, and cambium — the soft growing layer beneath outer bark. Aspen, willow, maple, birch, and various conifers are common winter targets.
Feeding is deliberate rather than predatory. A porcupine climbs to a safe branch, gnaws bark in patches, and may linger in the same tree for nights in a row. High sodium demand drives occasional chewing of shed antlers, bones, plywood, and tools left outdoors — a behavior that brings them into conflict with people even though they do not hunt animals.
North American porcupines are primarily solitary and nocturnal. Individuals maintain overlapping home ranges but usually avoid prolonged contact outside the breeding season. Mothers care for young alone; adult males do not help raise offspring.
When threatened, a porcupine faces away, raises its quills, and may stamp, chatter, or strike with the tail. Predators that specialize on porcupines, especially fishers, attack the unprotected face and underside. Wolves, coyotes where present, bobcats, cougars, and large owls also take porcupines opportunistically, but many carnivores learn to avoid a defensive adult. On the forest floor they can look awkward, yet they climb steadily and rest for long periods high in the canopy.
Breeding typically peaks in late autumn and early winter. After a long gestation of about seven months (~210 days), the female usually gives birth to a single offspring, called a porcupette, in spring or early summer. Twins are rare.
Porcupettes are born with eyes open and soft quills that harden within hours. They nurse for weeks to months while gradually sampling plant foods, and they can climb early. The mother–young bond lasts through the first summer and into autumn before the porcupette becomes independent. Sexual maturity is often reached in the second year. Wild lifespan is commonly estimated around 5 to 7 years; animals in human care may live 15 to 20 years.
(Population and conservation trend data sourced from the IUCN Red List of Threatened Species)
The North American porcupine is classified as Least Concern, with a generally stable population across its wide range. It is not globally threatened, though local densities vary with forest condition, winter food, and predator presence.
Important sources of mortality include vehicle collisions, entanglement in fences, poisoning or shooting where animals damage timber or property, and predation — especially where fishers are abundant. Intensive forestry can reduce preferred browse and den trees, while climate and forest composition shifts slowly reshape habitat suitability. Because the species still occupies a broad geographic footprint and reproduces reliably enough to persist in many managed forests, overall extinction risk remains low.
A North American porcupine may carry roughly 30,000 quills.
Porcupines cannot shoot their quills; quills detach on contact.
Quill tips are barbed, so they work deeper into flesh once lodged.
A baby porcupine is called a porcupette.
Fishers are one of the few predators that regularly kill porcupines.
Porcupines chew wood and antlers for minerals as well as food plants.
Select a question to reveal the answer.
The North American porcupine (*Erethizon dorsatum*) is a large, nocturnal rodent of the New World porcupine family Erethizontidae. It is covered in barbed quills and lives mainly in forests across Canada, Alaska, and much of the northern and western United States.
They inhabit forest habitats from Alaska and Canada south through New England, the Great Lakes region, the Rockies, and parts of the western United States. They climb trees for food and shelter and also travel across the forest floor at night.
Porcupines are strict herbivores. In winter they eat bark, cambium, twigs, and evergreen needles. In spring and summer they switch to leaves, buds, grasses, herbs, and fruit.
No. Quills are loosely attached and come free when they poke an attacker. Porcupines raise their quills, turn their back, and thrash the tail, but they cannot launch quills through the air.
A baby porcupine is called a porcupette. Females usually give birth to one porcupette after a long gestation of about seven months.
Yes. They are mainly nocturnal, resting in trees, dens, or rocky cover by day and climbing or foraging after dusk.
Their main defense is a coat of barbed quills. When threatened, a porcupine turns its quilled back toward the threat and may strike with its stout, quill-covered tail.
No. The species is listed as Least Concern, with a generally stable population. Local risks include vehicle collisions, habitat loss, and predation by fishers and other carnivores.
No. North American porcupines belong to family Erethizontidae and climb trees. African and Asian Old World porcupines belong to family Hystricidae (genus *Hystrix*) and are mainly ground-dwelling.
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