Rock cavies are large rodents and like other species of cavies the tail in this species is absent. These animals have whitish throats, grey dorsum and light brown stomach. They have porcupine-like jaw muscles. Young Rock cavies look similar to adults.
Rock cavies are found in South America. They range from eastern Brazil, from eastern Piauí state to Minas Gerais state. These animals have been introduced to the oceanic island of Fernando de Noronha. Rock cavies inhabit dry, rocky areas with low, scrubby vegetation, and they like to reside close to stony mountains and hills.
Rock cavies are social and live in large groups. Each group has an alpha or dominant male and several females. The males are territorial and defend rock pile shelters against other adult males. These rock piles are built to impress the females. Once a female chooses a rock pile, she indirectly chooses the builder as her mate. Rock cavies are very good climbers and they are often seen foraging in treetops. These animals are active at day and night but mostly at dawn or dusk. They usually shelter in crevices. Rock cavies communicate through a variety of vocalizations, many of which show anxiety or fear. They also socialize through allogrooming and such agonistic interactions as head thrusts and chases.
Rock cavies are polygynous, which means that males mate with more than one female during the breeding season. These animals breed year round. Females give birth to one or two young only, but several litters per year are common. The gestation period averages 75 days. Young are born well devloped and become weaned at 35 days. Both male and female Rock cavies care for their young. When both parents are present, the females spend more time with their young than the males do. When the males are absent, the females spend more time with their young than they do when the father is present. Females who raise young on their own are more aggressive than females that raise the young with a partner. Rock cavies reach reproductive maturity at around 133 days of age.
Rock cavies are frequently hunted as food by local human populations. This resulted in 30% of the population decline in the last ten years. Their environment is also being destroyed due to deforestation. There are also efforts to breed Rock cavies in captivity as a potential food source.
According to IUCN, Rock cavies are locally common throughout their range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.