North American Porcupine

The **North American porcupine** (*Erethizon dorsatum*), also known as the **Canadian porcupine** or **common porcupine**, is a large rodent in the New World porcupine family. The beaver is the only rodent in North America that is larger than the North American porcupine. The porcupine is a caviomorph rodent whose ancestors rafted across the Atlantic from Africa to Brazil over 30 million years ago, and then migrated to North America during the Great American Interchange after the Isthmus of Panama rose 3 million years ago.

## Characteristics

The North American porcupine is a rodent. It has black to brownish-yellow fur and strong, short legs. It has hairless soles on its feet that help it climb trees. It has a round body, small ears and a small head. The most recognizable feature of the porcupine is its quills. A porcupine may have as many as 30,000 quills. The quills are hairs with barbed tips on the ends. Quills are solid at the tip and base and hollow for most of the shaft. The porcupine has quills on all parts of its body, except for its stomach. The longest quills are on its rump. The shortest quills are on its cheeks.

The porcupine uses its quills for defense. The porcupine cannot shoot its quills. When a predator approaches, the porcupine will turn its back, raise the quills and lash out at the threat with its tail. If the porcupine hits an animal with its quills, the quills become embedded in the animal. Body heat makes the barbs expand and they become even more deeply embedded in the animal's skin. If an animal is hit in a vital place it may die. The porcupine is not an aggressive animal. It will only attack if it is threatened. Some animals, like the fisher, are experts at attacking porcupines.

## Range and Habitat

The North American porcupine can be found in most of Canada and the western United States south to Mexico. In the eastern United States, it can be found in Wisconsin, Michigan, Pennsylvania, New York and New England. The North American porcupine lives in coniferous, deciduous and mixed forests. In the west, it can be found in scrubby areas.

## Diet

The porcupine is an herbivore. It eats leaves, twigs and green plants like skunk cabbage and clover. In the winter, it may eat bark. It often climbs trees to find food. It is mostly nocturnal, but will sometimes forage for food in the day.

## Life Cycle

Porcupines mate in late summer and early fall. Porcupines are very vocal during mating season. Males often fight over females. The male performs an elaborate dance and sprays urine over the head of the female. Seven months after mating the female gives birth to a single baby. When the baby is born, its quills are soft. They harden about an hour after birth. The baby is begins to forage for food after only a couple of days. The baby will stay with its mother for about six months.

## Behavior

The North American porcupine is a solitary animal, although it may den with other porcupines in the winter. It makes its den in caves, decaying logs and hollow trees. The North American porcupine doesn't hibernate, but it may stay in its den during bad weather. The North American porcupine is a good swimmer, its hollow quills help keep it afloat. It is also an excellent tree-climber and spends much of its time in trees. It is a very vocal animal and has a wide-variety of calls including moans, grunts, coughs, wails, whines, shrieks and tooth clicking.