| North American Porcupine Temporal range: Late Pliocene - Recent |
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| BioDome, Montreal | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Erethizontidae |
| Subfamily: | Erethizontinae |
| Genus: | Erethizon F. Cuvier, 1823 |
| Species: | E. dorsatum |
| Binomial name | |
| Erethizon dorsatum (Linnaeus, 1758) |
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| Subspecies[2] | |
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| Synonyms | |
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Erethizon dorsata[2] |
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The North American Porcupine (Erethizon dorsatum), also known as Canadian Porcupine or Common Porcupine, is a large rodent in the New World porcupine family. The Beaver is the only rodent larger than the North American Porcupine found in North America. The porcupine is a caviomorph rodent whose ancestors rafted across the Atlantic from Africa to Brazil over 30 million years ago, and then invaded North America during the Great American Interchange after the Isthmus of Panama rose 3 million years ago.[3]
This animal is usually found in coniferous and mixed forested areas in Canada, Alaska and much of the northern and western United States, although rare, sustainable, breeding populations of porcupines are known to exist in West Virginia[4] and in smaller numbers in nearby regions of western Virginia.[5] They are also found in thicketed areas in shrublands, tundra and deserts as far south as northern Mexico. They make their dens in holes in trees or in rocky areas.
Porcupines are usually dark brown or black in color, with white highlights. They have a chunky body, a small face, short legs and a short thick tail. This species is one of the largest North American rodents, second only to the American beaver in size. The head-and-body length is 64.5 to 103 cm (25.4 to 41 in), not counting a tail of 14.5 to 30 cm (5.7 to 12 in). The hindfoot length is 7.5 to 9.1 cm (3.0 to 3.6 in). Weight can range from 3.5 to 18 kg (7.7 to 40 lb), although they average under 9 kg (20 lb).[6][7] Their upper parts are covered with thousands of sharp, barbed hollow spines or quills (actually modified hairs), which are used for defense. Porcupines do not throw their quills, but the quills detach easily and the barbs make them difficult to remove once lodged in an attacker. The quills are normally flattened against the body unless the animal is disturbed. The porcupine also swings its quilled tail towards a perceived threat.
Porcupines are nearsighted and slow-moving. Porcupines are selective in their eating; out of 1000 trees in the Catskill forest, one or two are acceptable lindens, and one is a bigtooth aspen. Consequently, the porcupine has "an extraordinary ability to learn complex mazes and to remember them as much as a hundred days afterward".[8]
The porcupine is the only native North American mammal with antibiotics in its skin. Those antibiotics prevent infection when a porcupine falls out of a tree and is stuck with its own quills upon hitting the ground. Porcupines fall out of trees fairly often because they are highly tempted by the tender buds and twigs at the ends of the branches. The porcupine and the skunk are the only North American mammals that are black and white, because they are the only mammals that benefit from letting other animals know where and who they are in the dark of the night.[8]
Porcupines are mainly active at night; on summer days, they often rest in trees. During the summer, they eat twigs, roots, stems, berries and other vegetation. In the winter, they mainly eat conifer needles and tree bark. They do not hibernate but sleep a lot and stay close to their dens in winter. The strength of the porcupine's defense has given it the ability to live a solitary life, unlike many herbivores, which must move in flocks or herds.
Porcupines breed in the fall and the young porcupine (usually one) is born in the spring, with soft quills that harden within a few hours after birth. When porcupines are mating, they tighten their skin and hold their quills flat, so as not to injure each other.[9]
They are considered by some to be as a pest because of the damage that they often inflict on trees and wooden and leather objects. Plywood is especially vulnerable because of the salts added during manufacture. The quills are used by Native Americans to decorate articles such as baskets and clothing. Porcupines are edible and were an important source of food, especially in winter, to the Natives of Canada's boreal forests. They move slowly (having few threats in its natural environment which would give it the need to flee quickly) and are often hit by vehicles while crossing roads. Natural predators of this species include fishers (a marten-like animal), wolverines, coyotes, wolves, bears and cougars as well as humans. Due to its dangerous quills, the North American Porcupine is often avoided as prey and even regular predators may be harmed or killed by their quills. Most predators of the porcupine will attempt to stun or cause massive blood loss with an attack to the face and then will spin them over to their unprotected underside. The porcupine can embed several painful quills directly into a predator's face, which may save their own lives. In order to avoid predation, porcupines often climb trees at the sign of danger, since most of their natural predators cannot pursue them once they're arboreal.[10]
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