Animal Tracks - Porcupine (Erethizon dorsatum)

Porcupine

Erethizon dorsatum

Porcupine Tracks and Trail Pattern

Natural History of Porcupines

Porcupines are nocturnal vegetarians, but can be active by day. They eat the inner bark, or cambium, of trees. They will also eat foliage, twigs, bark, leaves, buds, fruits, berries, nuts, flowers, and will sometimes feed in fields.
They move slowly and don't see well. They climb trees to escape predators, but will use their quills if they have to.

Porcupines do not shoot their quills. The quills are loosely attached. If attacked, a porcupine slaps the attacker with its tail. Many dogs have ended up with a muzzle full of quills by getting too close to a porcupine. The quills have barbs and will work their way in deeper if left alone. A single porcupine may have 30,000 quills. Quills are modified hairs that have hollow shafts with solid tips and bases. The quills can be up to five inches long.

Newborn porcupines weigh more than grizzly bear cubs do at birth.

Their tracks show four toes on the front foot and five on the hind foot. Marks made by the long claws usually show. The heel pads have a pebbly texture. This acts as a non-slip surface and helps them climb trees. Sometimes, a tail drag mark is visible in the trail. Porcupine scat is in pellet form, and often found in piles at the base of a tree where the animal has been feeding. The picture above shows a tree damaged by a porcupine. This type of feeding sign is common.

Fishers are predators that can eat porcupines. They flip the porcupine over to get at the soft underside, which lacks quills.

Porcupines love salt and will chew on wooden tool handles that have absorbed perspiration to get the salt


Front foot of porcupine cast in plaster.	Hind foot of porcupine. Note the pebbly texture on both feet.

Personal Notes on Porcupines

The first porcupine I encountered was on the ground at Albee Creek Campground at Humboldt Redwoods State Park. It was winter, so the campground was closed. I was walking with a dog toward the creek when the dog started barking at something in the tall grass. I went to investigate and saw the porcupine with its back to me, quills showing. The dog had never seen one of these before and was curious. After I told the dog to back off several times, it got the idea and left the porcupine alone. The dog's curiosity could easily have resulted in a muzzle full of quills. The porcupine slowly waddled away.

prints prints

Got a porcupine story? E-mail me and tell me about it.

tracker777@hotmail.com

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Page updated: January 4, 2004