Common Porcupine (Erethizon dorsatum)

common porcupine


  • The common porcupine is a large, robust rodent. Adults weigh about 10 kilograms (22 pounds).


  • Has a thick tail, and short powerful legs with long curved claws.
  • Coat is composed of rows of dense, brown undercoat with yellow-tipped guard hairs.
  • Guard hairs alternate with rows of loosely attached quills that vary from 25 to 65 millimetres (1 to 2.5 inches) in length.
  • Quills taper to a sharp and stiff point that is covered with very small barbs.
  • Quills are hollow, thus reducing their weight and providing buoyancy when the animal occasionally swims.
  • Porcupines occur in all natural regions where there is sufficient vegetation, including the alpine subregion in summer.
Natural History


  • In summer, porcupines feed on green leaves of forbs, shrubs and trees. They climb trees with ease and spend much of their time foraging in the trees.
  • In winter, they feed on the inner bark (cambium), twigs and buds of trees.
Reproduction and Growth

Breeding Behaviour

  • Porcupines live by themselves, except during mating season in November and December.
  • Usually only one porcupine is born to each female from mid-May through July. The porcupine is the only North American rodent to give birth to precocial young.

Growth Process

  • The young are born covered with hair and quills, with eyes open, and they are able to move about soon after birth.
  • The quills are flat and limp at birth but soon dry in the air.
  • Young porcupines are quite large at birth, weighing about 500 grams (1.1 pounds).
  • Young follow their nomadic mothers for several weeks, although they are weaned in their second week.
Conservation and Management


The NAME is classified as Secure in the current General Status of Alberta Wild Species report. See:

Current management


Porcupine may be hunted, but not trapped, without a licence throughout the province, at all times of the year. See details in the Alberta Guide to Hunting Regulations. To view the guide online or to order a printed copy, visit the My Wild Alberta website at:

A pointed defence

Porcupines move about at a slow and plodding pace, and are easily overtaken by most animals. However, their impressive defence system discourages attack by wolves, coyotes or other predators. A porcupine will turn its tail to an attacker and cover its unprotected face. If the attacker gets too close, the porcupine will lash out with its spiny, club-like tail. The blows from the tail are delivered swiftly, and the loose quills are easily detached from the porcupine's skin.

The barbed quills can be quite painful and prevent the attacker from feeding, especially if they are impaled in the mouth or paws. The barbs on the quills prevent easy removal and promote movement deeper into the victim. Thus, the quills can kill an animal weeks after an attack.


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Updated: May 12, 2010