SPINY RATS – Echimyidae



The physical characteristics of spiny rats vary greatly from species to species, from rat-sized to the size of a small cat. Their head and body length is from 4.13 to 18.9 inches (10.5 to 48 centimeters) and a tail length of 0.2 to 16.6 inches (0.5 to 42 centimeters). They weigh from 0.46 to 2.9 pounds (210 to 1,300 grams). In appearance, most species of spiny rat are rat-like, with pointed noses, although several species have blunt noses and resemble squirrels. Their front feet have four toes while their hind feet have five.

Spiny rats got their name because most species have spiny or bristly fur, most noticeably on their backs and rumps. The spiny qualities vary between species: the armored rat has welldeveloped spines, spiny rats, or casiragua, have broad and stiff hair, and the punaré has soft fur with no hint of spines.

Fur color also varies greatly between species, with upper body fur being gray or various shades of brown, and white or cream on their undersides. Several species, including the toro and the white-faced arboreal spiny rat have black-and-white or white faces.


Spiny rats are found throughout southern Central America and northern and central South America, from southern Honduras to northern Argentina and Chile.


Spiny rats live in a wide variety of habitats, from species that live exclusively in treetops, to forest floor dwellers to those that live underground in complex burrow systems. Many species live near the coast, rivers, or streams. The rato de Taquara lives exclusively in bamboo thickets along stream and river banks. They are found in both old growth and new-growth forests, but are most abundant in forests of intermediate age where there are large numbers of fruit trees, such as palm and fig. Spiny rats are often the most abundant animal in their geographic range.


Spiny rats are mostly herbivores, meaning they eat only plants, although some species eat insects. Their diet includes fruits, nuts, grass, and sugar cane. Several species, including rato de Taquara, eat only bamboo shoots and leaves.


Spiny rats are nocturnal, meaning they are mostly active at night. Most die if they are exposed to heat or dryness. Depending on the species, they live either individually, in small groups, or like the broad-headed spiny rat, in large colonies. The average lifespan is two to four years in the wild.

They are generally territorial, meaning they are protective of an area they consider home and claim exclusively for themselves. Males and females have separate territories. Males defend their burrows against other males but females are less aggressive and their territories frequently overlap. Territories are usually small, from 1.2 to 14.8 acres (0.5 to 6 hectares) and can vary greatly between the seasons.

Spiny rats play a critical role in the health of the rainforest of Central and South America by dispersing the seeds from a wide variety of trees and other forest plants through their excretions. They are also an important source of food for predators such as ocelots, owls, boa constrictors, anacondas, and jaguars.

Little is known about the breeding habits of many species. In general, spiny rats breed throughout the year and females can give birth to four to six litters a year. The litter size ranges from one to seven babies, with the average being two to four. Gestation period, the time the female carries the young in her womb, varies but is generally sixty to seventy days. In the punaré, a species of spiny rat, the females produce two or three litters per year and gestation period is from ninety-five to ninety-eight days.


Several species are hunted and eaten by humans, some are killed by farmers who consider them agricultural pests, and several species are used as laboratory animals.


The IUCN lists three species of spiny rats as Extinct, or died out; one species as Critically Endangered, facing an extremely high risk of extinction; five species as Vulnerable, facing a high risk of extinction in the wild; and nine species are Near Threatened, not currently threatened, but could become so. The remaining species are not listed as threatened by the World Conservation Union (IUCN).