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Spiny Rats: Echimyidae

Spiny Rat (proechimys Semispinosus): Species Account

Physical characteristics: The spiny rat is about the size of a common house rat, except with a larger head and smaller ears. Head and body length is 6.4 to 12 inches (16.0 to 30.0 centimeters) and a tail length of 4.4 to 12.8 inches (11.2 to 32.5 centimeters). They weigh from 10.5 to 17.5 ounces (300 to 500 grams). Their fur is orange-brown on the upper body and white underneath.

Geographic range: The spiny rat is found in Colombia, Costa Rica, Ecuador, Honduras, Nicaragua, and Panama.

Habitat: The spiny rat lives in rainforest, usually in dense underbrush and near rivers and streams.

The spiny rat doesn't dig its own burrow, but will live in burrows dug by other animals. Males defend the burrow against other males. (Illustration by Barbara Duperron. Reproduced by permission.)

Diet: They are mostly herbivores, feeding primarily on fallen fruit but sometimes on fungi.

Behavior and reproduction: The spiny rat is nocturnal, meaning it is mostly active at night. It sleeps, nests, and stores food in burrows dug by other animals, rock crevices, or hollows in trees or logs. It does not dig its own burrow. The male defends its burrow against other males. The lifespan of the spiny rat is two to four years.

The species breeds throughout the year and the females may have three to six litters per year. The gestation period, the time the female carries a litter in her womb, is sixty-three to sixty-six days, with the number of babies ranging from one to five. They reach sexual maturity at six to seven months.

Spiny rats and people: Spiny rats are trapped and eaten by local people.

Conservation status: The IUCN does not consider the spiny rat to be threatened. ∎



Leite, Yuri L. R. Evolution and Systematics of the Atlantic Tree Rats, Genus Phyllonrys (Rodentia, Echimyidae). Berkeley, CA: University of California Press, 2003.

Macdonald, David. The New Encyclopedia of Mammals. Oxford, U.K.: Oxford University Press, 2001.

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

Wilson, Don E., and DeeAnn M. Reeder. Mammal Species of the World— A Taxonomic and Geographic Reference, 2nd ed. Washington, DC: Smithsonian Institution Press, 1993.


Adler, Gregory H. "Impacts of Resources on Populations of a Tropical Forest Rodent." Ecology (January 1998): 242–255.

Lambert, Thomas D., and Gregory H. Adler. "Microhabitat Use by a Tropical Forest Rodent, Proechimys semispinosus, in Central Panama." Journal of Mammalogy (February 2000): 70–76.

Lara, Marcia C., and Patton, James L. "Evolutionary Diversification of Spiny Rats (Genus Trinomys, Rodentia: Echimyidae) in the Atlantic Forest of Brazil." Zoological Journal of the Linnean Society (December 2000): 661–686.

Marcomini, Monique, and Elisabeth Spinelli de Oliveira. "Activity Pattern of Echimyid Rodent Species from the Brazilian Caatinga in Captivity." Biological Rhythm Research (April 2003): 157–166.

Matacq, Marjorie D, et al. "Population Genetic Structure of Two Ecologically Distinct Amazonian Spiny Rats: Separating History and Current Ecology." Evolution (July 2000): 1423–1432.

Morato, Manaf P., et al. "Profile of Wild Neotropical Spiny Rats (Trinomys, Echimyidae) in Two Behavioral Tests." Physiology and Behavior (July 2003): 129–133.

Web sites:

Myers, Phil. "Family Echimyidae." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Echimyidae.html (accessed on July 12, 2004).

Additional topics

Animal Life ResourceMammalsSpiny Rats: Echimyidae - Physical Characteristics, Habitat, Behavior And Reproduction, Spiny Rat (proechimys Semispinosus): Species Account - GEOGRAPHIC RANGE, DIET, SPINY RATS AND PEOPLE, CONSERVATION STATUS