Hystrix sumatrae is found exclusively on Sumatra, one of the islands composing the Indonesian archipelago.

Biogeographic Regions: oriental (Native )

Other Geographic Terms: island endemic

Sumatran porcupines are relatively small. Measured from the nose to the tip of the hind feet, they range in size from 45 to 56 cm with a mean of 54 cm. Tail length ranges from 2.5 to 19 cm with a mean of 10 cm. They weigh between 3.8 and 5.4 kg. Sumatran porcupines are covered in sharp flattened quills, rattle quills, and stiff bristles. Quills and bristles can be up to 16 cm long and are smaller and more flexible on their cheeks, underside, and feet. Rattle quills are located on the tail and have hollow tips, producing a hiss-like rattle sound when shaken. Rattle quills do not develop until maturity. Sumatran porcupines are dark brown in color, although roughly half of their quills and bristles are white tipped, giving them a distinctly speckled, grey appearance. They often have dirty-white patches on the underside of their neck. Sumatran porcupines do not have a crest, as found in some other members of the genus Hystrix.

Hystrix sumatrae was originally included in Hystrix crassipinis, a very similar species found on the neighboring island of Borneo. The two were later separated on basis of body size and quill diameter. Hystrix sumatrae is smaller in size and has much thinner quills than H. crassipinis.

Range mass: 3.8 to 4.6 kg.

Average mass: 4.7 kg.

Range length: 45 to 56 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

• Terrestrial

Sumatran porcupines live in the tropical rainforests that cover the island of Sumatra. They are terrestrial animals and prefer rugged, rocky areas. They make dens in small caves, under fallen trees and stumps, between rocks, and in small burrows. Sumatran porcupines can adapt to a wide variety of habitats. They are at home in forests as well as on cultivated or cleared land. Elevational data for Sumatran porcupines does not exist; however, a closely related species, long-tailed porcupines (found on the neighboring island of Borneo), live at elevations from sea level to 1200 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

Other Habitat Features: agricultural

Sumatran porcupines are herbivorous, feeding on a variety of plant material including bark, roots, tubers, fruits, and bulbs. They also like cultivated crops, such as sweet potatoes, bananas, peanuts, maize, sugar cane, beans, melons and mango. Feeding on carrion (animal remains) has been reported for other members of the genus Hystrix, but is not common. Sumatran porcupines forage at night, typically alone, but occasionally accompanied by one or two offspring. An individual may travel many kilometers a night looking for food, usually along well developed tracks and trails.

Many porcupines also forage for bones. They carry them back to their den and gnaw on them, partially in an effort to wear down and sharpen their teeth, but also to obtain minerals like calcium and phosphate that may be lacking in their diets. Piles of gnawed bones often litter the entrances to dens.

Plant Foods: roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit

Primary Diet: herbivore (Frugivore , Granivore , Lignivore)

Sumatran porcupines are hunted for their meat by humans and may be preyed upon by other animals. They are herbivores and might also serve an ecological role as seed dispersers by eating and defecating plant material. Burrows likely increase soil aeration and water penetration to the surrounding environment. They are also host to a number of ectoparasites, including fleas, ticks, and mosquitoes, and are known to carry and transmit bubonic plague and malaria.

Ecosystem Impact: disperses seeds

Commensal/Parasitic Species:

• fleas (<< Siphonaptera>>)
• ticks (Ixodoidea)
• mosquitoes (Culicidae)
• bubonic plague (Yersinia pestis)
• malaria (Plasmodium)

There are no major predators reported for Sumatran porcupines. This could be in part due to their ability to defend themselves, as their quills provide excellent protection. While quills cannot be launched, they are detachable and easily penetrate and stick into skin. They are not poisonous, but may cause infections that can prove fatal.

Sumatran porcupines use anal scent glands to mark their territories. Males frequently mark high quality feeding patches.  It is easy to tell when Sumatran porcupines are alarmed because of their display. They stamp their feet, erect and rattle their quills, and raise their rears. If approached, they run backwards or sideways toward the threat, attempting to impale it with their quills. They may also stamp their feet, grunt, and whine to communicate with enemies of the same or different species, as well as in courtship and mating. In other species of the genus Hystrix potential mates engage in a "dance" on their hind legs while humming and grunting together. They may put their paws on each others' shoulders and rub noses. In many genera of Old World porcupines, males urinate on females during courtship.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; acoustic

There are no records of the lifespan of of Hystrix sumatrae in the wild. There is one report of a single individual in captivity that was alive after 13.3 years. Related species have life spans in the wild ranging from 12 to 20 years, and have been reported to live up to 27 years in captivity (Hystrix brachyura); however, 9 to 15 year life spans are much more common.

Range lifespan

Status: captivity: 13.3 (high) years.

There is no information concerning the mating system of Hystrix sumatrae. In most congeners, males and females form monogamous relationships.

In similar species, males court females by showering them with urine. If the female refuses the male, she repsponds aggresively. If the female is receptive, she raises her tail and rear and allows him to mate with her. Both males and females can be vocal during mating, producing a variety of whines, grunts, and squeals. Most members of the genus Hystrix have an estrus cycle of 28 to 36 days and a gestation period of 93 to 110 days. Breeding generally occurs once a year, during late winter or early spring (December through March). For related species of the genus Hystrix litter sizes are small, consisting of one or two precocial young in late summer. Their quills harden within a few hours after birth, and they begin to eat solid food around 9 days old but continue to nurse for up to 19 weeks. Young porcupines reach sexual maturity between 9 months and 2 years of age.

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Within the genus Hystrix, both males and females participate in parental care. Females gestate young, and following birth, lactate for up to 19 weeks. Males aggressively defend young and their burrows. Both parents accompany young while foraging for 6 to 7 months after birth, though males are found with young more often than females.

Parental Investment: precocial ; male parental care ; female parental care ; pre-fertilization (Provisioning); pre-hatching/birth (Provisioning: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male); pre-independence (Provisioning: Male, Female, Protecting: Male)

Sumatran porcupines are listed as a species of "least concern" on the IUCN's Red List of Threatened Species. Their low priority status is due to their wide distribution over throughout Sumatra, their adaptability, and their broad range of habitats and foods. They are also found within protected areas on the island of Sumatra.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Sumatran porcupines are major agricultural pests throughout their range. They not only eat the plant material itself, but they also damage trees by gnawing on branches, trunks, and bark to wear down their ever-growing teeth. They can also transmit human diseases, especially those associated with fleas and ticks. Members of the genus Hystrix have been known to carry and transmit the bubonic plague and malaria.

Negative Impacts: injures humans (carries human disease); crop pest

On the island of Sumatra, Hystrix sumatrae is hunted for meat and recreation. Its quills are used for ornamentation and talismans. Porcupines may also be valuable seed dispersers.

Positive Impacts: food ; body parts are source of valuable material