NEW WORLD PORCUPINES: Erethizontidae

PHYSICAL CHARACTERISTICS

New World porcupines are some of the largest North American rodents. They are stocky animals with many sharp quills, modified guard hairs, and spines that in most species are hidden beneath long fur but are visible in others. Quills lie facing downward and spines cover most of their upper bodies and tail, except for a few species that have no spines. The animals have a prehensile, able to grasp by wrapping around, tail that can reach about one-fourth to over one-half its length. Its head consists of a blunt muzzle, small rounded eyes that are nearly hidden by hair, and small rounded ears. Its body has humped shoulders, short bowed legs, and long curved claws. Adults are 15.5 to 51.0 inches (40 to 130 centimeters) long and weigh between 6.5 and 22.0 pounds (3 to 10 kilograms).

GEOGRAPHIC RANGE

New World porcupines are found in North, Central, and South America, from Canada and Alaska to Argentina.

HABITAT

These porcupines live primarily in trees throughout rainforests and deciduous and coniferous woods, except for one species that lives in deserts and a few others that are found in plantations and other cultivated areas.

DIET

New World porcupines eat fruits, seeds, leaves, and bark.

BEHAVIOR AND REPRODUCTION

New World porcupines are assumed to be nocturnal, active at night, and arboreal, living in trees, spending their days sleeping in trees or in private ground places. They spend most of their time alone, but during winter months, several animals often share a winter den. Their winter territory averages 12 acres (5 hectares), while the larger summer territory reaches a maximum of 35 acres (14 hectares). Although not territorial, they defend feeding grounds during winters. They can spear their quills into attackers with spines that are detached. When faced with a predator, an animal that hunts and eats other animals, they erect their quills so they stick out in many directions and chatter their teeth. New World porcupines either remain stationary in a defensive position, or may charge the predator by quickly whipping out with their quill-laden tail.

Most of the time New World porcupines do not communicate with each other. Females do touch their young with their nose, giving them gentle grunts and whines. During the mating season, porcupines become noisy with various grunts, moans, screams, and barks. It is believed that females are either pregnant or lactating, producing milk, for most of their lives. The gestation period, the time period the offspring are in the womb, lasts about 200 days. When gestation is over the female mates again. Females nurse, feed on mother's milk, their newborns for eight to twelve weeks. A litter, young animals born together from the same mother, is usually only one young, which is born with fur and soft quills that harden quickly. The young reach adult size in about one year, and become sexually mature (able to mate) in one-and-a-half to two-and-a-half years. Their average lifespan is fifteen years.

NEW WORLD PORCUPINES AND PEOPLE

Some New World porcupines are hunted by people. The quills of some species are used in artwork.

CONSERVATION STATUS

New World porcupines are not threatened.

NORTH AMERICAN PORCUPINE (Erethizon dorsatum): SPECIES ACCOUNTS

Physical characteristics: North American porcupines have stiff, dark-brown or black hair on their back along with scattered white barbed quills at the head, rear of body, and on the tail. They may have more than 30,000 barbed quills, many of which have a yellow-white base with a dark tip. Their face is a dark brown, with a woolly belly that does not have quills. Their undersides are covered with stiff, dark hairs. North American porcupines have a short, thick tail that contains quills above and stiff bristles below and large, naked feet. Their large incisor teeth are deep orange. Adults have a length of about 39 inches (1 meter) with the tail being one-fifth to one-third of the total length. Body weight is less than 26 pounds (12 kilograms), but a large male can be up to 33 pounds (15 kilograms). Juveniles have a nearly all-black head, back, and tail. Their quills are short but sharp. Females have two pairs of mammae (MAM-ee), milk-secreting organ of female mammals.

Geographic range: North American porcupines range throughout Canada, except the far north-central regions, and down into the northeastern and north-central part of the United States and almost all of the western United States except the most southern regions. They also extend into the northern edge of central Mexico.

Habitat: North American porcupines are found in mixed hardwood and softwood forested areas, tundra, and occasionally in open areas and even deserts as long as plenty of water sources are around. They prefer rocky areas, ridges, and slopes.

Diet: North American porcupines are herbivores, animals that eat plant material, such as fruits, grains, and seeds. They feed on foliage for much the year and on inner bark of pine and oak trees in winter. They also eat seeds, fruits, nuts, berries, and plant stems, buds, twigs, leaves, roots, and flowers. Their chisel-like teeth scrape away the tough outer bark, and then slice off pieces of inner bark to eat. North American porcupines eat alone, except for mothers and their young. They feed at night, but sometimes during the day, especially if the weather has been bad.

Behavior and reproduction: North American porcupines are mostly arboreal and nocturnal animals. They are good at climbing trees, although their slow movements seem awkward, and are good swimmers. They use hollow trees and logs, or gaps beneath rocks for their winter dens. The animals normally live alone, but will share a winter den when few good locations are available. They are not territorial, but will defend a feeding site if resources are few. During the breeding season, females produce bodily odors to show males they are ready to mate. Several males fight over the right to mate with one female. One of their courtship rituals is for the male to spray the female with urine. When females are ready, they will dance with their chosen male, rising on their hind feet, embracing while whining and grunting loudly, and pushing one another playfully to the ground. Their main predators include mountain lions, lynx, fishers, coyotes, bobcats, red foxes, wolves, wolverines, and great horned owls. During winter months they stay close to their den but go further out during summer months.

They are polygynous (puh-LIH-juh-nus), having more than one mate. Mating occurs only once a year, in the late summer and early autumn, and only during an eight to twelve hour period when the female is receptive. Females give birth to one but sometimes to two young. The gestation period is about seven months. Young weigh about 1.0 to 1.1 pounds (450 to 490 grams) at birth, and are born with both spines and fur. They double their weight within the first two weeks. They usually feed on their mother's milk for only a short period then begin to feed on vegetation shortly after birth. They soon become entirely independent of the mother. Young males move in and out of the mother's range for months or years, while young females leave the range permanently. They become sexually mature at about one-and-a-half years and most can live to about fifteen years of age.

North American porcupines and people: Native Americans used their quills for artwork and as a type of currency. North American porcupines were also hunted for food. They are often considered as pests when they gnaw through valuable wood and trees.

Conservation status: North American porcupines are not threatened. ∎

PREHENSILE-TAILED PORCUPINE (Coendou prehensilis): SPECIES ACCOUNTS

Physical characteristics: Prehensile-tailed porcupines have a grayish to yellowish brown body with short, thick spines that are whitish or yellowish and mixed with darker hair. Their face is whitish and undersides are gray. Their padded feet have four long-clawed toes. The tail is small, long, black, and prehensile with a curled tip. The last one-third of the tail does not contain spines on its upper surface, which helps it to wrap around thin branches. Juveniles have an orangish brown to brown body with longer fur that sometimes hides its spines. Adults are 3 to 4 feet (0.9 to 1.2 meters) long with half of the length being its tail. They weigh between 9 and 12 pounds (4.0 and 5.5 kilograms).

Geographic range: They are found in eastern South America from eastern Venezuela and Trinidad to northeastern Argentina and Uruguay.

Habitat: The animals inhabit vine-covered rainforests and jungles, but can also be found in agricultural areas, gardens, and drier forests near water sources.

Diet: Prehensile-tailed porcupines are herbivores, eating mostly fruits, seeds, stems, leaves, roots, small twigs and shoots, and bark. They usually eat during the late part of the day.

Behavior and reproduction: Prehensile-tailed porcupines are shy, nocturnal porcupines that are solitary, alone, or live in pairs or gather in groups occasionally. They spend most of their time high in tree branches; going from tree to tree by climbing down one tree, walking across the ground, and climbing up another tree. The animals move slowly, but can move fast when they must. They are good climbers, mostly due to their long, prehensile tail and padded, clawed feet. Prehensile-tailed porcupines sleep during the day, usually within a clump of vegetation in the forest's canopy. When threatened by a predator, they are not aggressive but will defend themselves if attacked. Prehensile-tailed porcupines often roll into a ball and raise their quills. Sometimes they attack the predator by quickly moving toward the intruder with spines erect. They will also stomp feet, shake spines, and make threatening snarls and grunts. They communicate with each through long moaning sounds.

During breeding periods, a male will spray urine onto a female and may also spray newborns. Females reproduce about every seven months. They often give birth during the rainy season, but it is not clear if this is always the case. The gestation period is 195 to 210 days. After giving birth usually to one young, the female will almost immediately mate again. Newborns are covered with red hairs and small spines, which harden shortly after birth. Young are weaned, no longer fed its mother's milk, after three months. Adulthood is reached in about eleven months and sexual maturity in about nineteen months.

Prehensile-tailed porcupines and people: People occasionally hunt prehensile-tailed porcupines for food. They are sometimes considered an agricultural pest.

Conservation status: Prehensile-tailed porcupines are not threatened. ∎

FOR MORE INFORMATION

Books:

Feldhemer, George A., Lee C. Drickamer, Stephen H. Vessey, and Joseph F. Merritt. Mammalogy: Adaption, Diversity, and Ecology. Boston: WCB McGraw-Hill, 1999.

Nowak, Ronald M. Walker's Mammals of the World, 6th ed. Vol. 2. Baltimore and London: The Johns Hopkins University Press, 1999.

Vaughan, Terry A., James M. Ryan, and Nicholas J. Czaplewski. Mammalogy, 4th ed. Philadelphia: Saunders College Publishing, 2000.

Whitfield, Philip. Macmillan Illustrated Animal Encyclopedia. New York: Macmillan Publishing Company, 1984.

Wilson, Don E., and DeeAnn M. Reeder, eds. Mammal Species of the World, 2nd ed. Washington, DC and London: Smithsonian Institution Press, 1993.