The small mammal is endemic to the Moleques do Sul Archipelago [pt], located in the state of Santa Catarina in southern Brazil.

The archipelago formed about 8,000 years ago, having a total of three islands with a surface area of only 10.5 hectares (26 acres).

[2] When population densities were estimated, two techniques were used, one was determined using trapping grids, which is usually placed in optimum habitat, which would be only 0.77ha, which are their feeding grounds.

The other method was minimum-number-known-alive (MNKA),[5] covering the 6.34 ha of vegetation used by the cavies known due to sited feces.only aproximately 20-24 Santa Catarina guinea pigs are alive as of 2024.

Bushes and grasses such as Cortaderia selloana and Verbesina glabrata surround the grazing grounds and supply protection and shelter to these insular cavies.

Moleques do Sul guinea pigs are also vulnerable to the burrowing owl and periguine falcon, which were not observed over the course of research.

The higher ratio is related to high population density corresponding to direct contact between the insular cavies, allowing mites and louse species to spread to nearby hosts.

The lifespan of these cavies is not well known due to limited data and lack of research; however Moleques do Sul guinea pigs had an average monthly survival rate of (0.81) which is high for a species within a small geographic location.

Communication and socialization is assumed different in C. intermedia populations than with C. magna and other Cavia species due to similar home-range sizes.

[7] Because of the species' low population size and small geographic location, C. intermedia is considered Critically Endangered.

Due to the cavies small feeding patch of 0.77 ha overexploitation when the population density is higher creates a natural fluctuation in the mortality of the species.