Porcupine Facts

The porcupine is any of 58 species of large, quill-coated rodents in the families Erethizontidae and Hystricidae. The New World porcupines are in family Erethizontidae and the Old World porcupines are in family Hystricidae. The common name "porcupine" comes from a Latin phrase that means "quill pig."

Description

Porcupines have rounded bodies covered with fur in shades of brown, white, and gray. Size varies according to species, ranging from 25 to 36 inches long plus an 8 to 10 inch tail. They weigh between 12 and 25 pounds. Old World porcupines have spines or quills grouped in clusters, while the quills are attached separately for New World porcupines. The quills are modified hairs made of keratin. While they have relatively poor vision, porcupines have an excellent sense of smell.

Habitat and Distribution

Porcupines live in temperate and tropical regions in North and South America, Africa, southern Europe, and Asia. New World porcupines prefer habitats with trees, while Old World porcupines are terrestrial. Porcupine habitats include forests, rocky areas, grasslands, and deserts.

Diet

Porcupines are primarily herbivores that feed on leaves, twigs, seeds, green plants, roots, berries, crops, and bark. However, some species supplement their diet with small reptiles and insects. While they do not eat animal bones, porcupines chew on them to wear down their teeth and obtain minerals.

Behavior

Porcupines are most active at night, but it's not unusual to see them foraging during the day. The Old World species are terrestrial, while the New World species are excellent climbers and may have prehensile tails. Porcupines sleep and give birth in dens made in rock crevices, hollow logs, or under buildings.

The rodents display several defensive behaviors. When threatened, porcupines raise their quills. The black and white quills make the porcupine resemble a skunk, particularly when it's dark. Porcupines chatter their teeth as a warning sound and shiver their bodies to display their quills. If these threats fail, the animal releases a pungent odor. Finally, a porcupine runs backwards or sideways into the threat. While it cannot throw quills, the barbs on the end of the spines help them to stick on contact and make them difficult to remove. The quills are coated with an antimicrobial agent, presumably to protect porcupines from infection resulting from self-injury. New quills grow to replace those that are lost.

Reproduction and Offspring

Reproduction differs somewhat between Old World and New World species. Old World porcupines are monogamous and breed several times a year. New World species are only fertile for 8 to 12 hours during the year. A membrane closes off the vagina the rest of the year. In September, the vaginal membrane dissolves. Odors from the female's urine and vaginal mucus attract males. Males fight for mating rights, sometimes maiming or scarring competitors. The winner guards the female against other males and urinates on her to check her willingness to mate. The female runs away, bites, or tail-swipes until she is ready. Then, she moves her tail over her back to protect her mate from quills and presents her hindquarters. After mating, the male leaves to seek other mates.

Gestation lasts between 16 and 31 weeks, depending on the species. At the end of this time, the females usually gives birth to one offspring, but sometimes two or three young (called porcupettes) are born. Porcupettes weigh about 3% of their mother's weight at birth. They are born with soft quills, which harden within a few days. Porcupettes mature between 9 months and 2.5 years of age, depending on the species. In the wild, porcupines typically live up to 15 years. However, they can live to 27 years, making them the longest-lived rodent, after the naked mole rat.

Conservation Status

Porcupine conservation status varies according to species. The International Union for Conservation of Nature (IUCN) classifies some species as "least concern," including the North American porcupine (Erethizon dorsatum) and long-tailed porcupine (Trichys fasciculata). The Philippine porcupine (Hystrix pumila) is vulnerable, the dwarf porcupine (Coendou speratus) is endangered, and several species have not been evaluated due to lack of data. Populations range from stable to decreasing in number.

Threats

Threats to porcupine survival include poaching, hunting and trapping, habitat loss and fragmentation due to deforestation and agriculture, vehicle collisions, feral dogs, and fires.

Porcupines and Humans

Porcupines are eaten as food, especially in Southeast Asia. Their quills and guard hairs are used to make decorative clothing and other items.

Sources

• Cho, W. K.; Ankrum, J. A.; et al. "Microstructured barbs on the North American porcupine quill enable easy tissue penetration and difficult removal." Proceedings of the National Academy of Sciences. 109 (52): 21289–94, 2012. doi:10.1073/pnas.1216441109
• Emmons, L. Erethizon dorsatum. The IUCN Red List of Threatened Species 2016: e.T8004A22213161. doi:10.2305/IUCN.UK.2016-3.RLTS.T8004A22213161.en
• Guang, Li. "Warning Odor of the North American Porcupine." Journal of Chemical Ecology. 23 (12): 2737–2754, 1997. doi:10.1023/a:1022511026529
• Roze, Locke and David Uldis. "Antibiotic Properties of Porcupine Quills." Journal of Chemical Ecology. 16 (3): 725–734, 1990. doi:10.1007/bf01016483
• Woods, Charles. Macdonald, D. (ed.). The Encyclopedia of Mammals. New York: Facts on File. pp. 686–689, 1984. ISBN 0-87196-871-1.