Porcupines

The North American porcupine has a head-and-body length that averages about 30 in (76 cm), with an upward-angled tail 9 to 10 in (23-25 cm) long. A male porcupine weighs about 14 lb (6.4 kg), with the female several pounds less. An adult porcupine possesses about 100 quills per square inch (about per 6 sq cm) from its cheeks, on the top of its head, down its back and onto its tail. There are no quills on its undersides or on the hairless bottom of its feet.

Porcupines are primarily woodland and forest animals of all parts of Canada except the Arctic islands and the United States except the prairie states and Southeast. Nocturnal animals, they readily climb trees, gripping with powerful, curved claws, and may even stay up in the branches for several days at time. They have typical rodent front teeth. These long incisors are orange in color and they grow continuously. Like beavers, porcupines munch bark off trees, although they prefer vegetables and fruits. In spring, however, they go after new buds and leaves. They often swim in order to reach water plants. They are made buoyant by their hollow quills.

One of the few animals that willingly takes on a porcupine is the weasel called a fisher. It teases the animal until it is worn out and easily turned over, where its unquilled underparts can be attacked. Some areas of the country that are being overrun by porcupines have introduced fishers to help eliminate them.

In winter, a porcupine develops a thick, woolly coat under its guard hairs and quills. It will spend much of its time in a den, which is usually a hollow tree, cave, or burrow dug by another animal. It does not hibernate or even sleep more than usual. It goes out regularly in the winter to feed.

Adult porcupines are solitary creatures except when mating, after which the male disappears and is not seen again. After a gestation of 29 to 30 weeks, usually a single well-developed baby, sometimes called a porcupette, is born in an underground burrow. The quills of a newborn are few and soft, but they harden within a few hours. The young stay with the mother for about six months before going off on their own. They become sexually mature at about 18 months and live to be about 10 years old if they can avoid cars on highways.

The Brazilian thin-spined porcupine (Chaetomys subspinosus) has quills only on its head. Another species, the prehensile-tailed porcupine (Coendou prehensilis) has a tail almost as long as its body, which can be wrapped around a tree branch to support the animal.