Some food, in the form of roots, stems, and grass, is probably pulled into the burrows from below. The diet is thought to be entirely vegetarian. In most species a burrow is occupied by a single individual, but several female C. peruanus may share the same system. This call is made mainly by the males, probably to show territoriality or fear. A single vocalization lasts from 10 to 20 seconds, starting slowly and then becoming more rapid.
Females are generally monestrous and produce only a single litter per year.
In Peru C. opimus mates in the dry season, and most births occur in the wet season, when plant growth is at its peak. In Argentina C. talarum mates from May to July. Newborn C. peruanus are well developed and are able to give the same call as adults, to leave the nest, and to feed on green vegetation almost immediately. The young of captive C. talarum, however, do not have their eyes open at birth and have only the guard hairs projecting through the skin. They weigh about eight grams each.